Nothing
R/do_findChromPeaks-functions.R
In xcms: LC-MS and GC-MS Data Analysis
Defines functions
.narrow_rt_boundaries
.getRtROI
peaksWithCentWave
peaksWithMatchedFilter
do_findChromPeaks_addPredIsoROIs_mod
do_findChromPeaks_addPredIsoROIs
do_findChromPeaks_centWaveWithPredIsoROIs
do_findKalmanROI
do_define_adducts
do_define_isotopes
.MSW_orig
.MSW_orig
do_findPeaks_MSW
.matchedFilter_binYonX_no_iter
.matchedFilter_orig
do_findChromPeaks_matchedFilter
do_findChromPeaks_massifquant
.centWave_new
.centWave_orig
do_findChromPeaks_centWave
Documented in
do_findChromPeaks_addPredIsoROIs
do_findChromPeaks_centWave
do_findChromPeaks_centWaveWithPredIsoROIs
do_findChromPeaks_massifquant
do_findChromPeaks_matchedFilter
do_findPeaks_MSW
peaksWithCentWave
peaksWithMatchedFilter
## All low level (API) analysis functions for chromatographic peak detection
## should go in here.
#' @include c.R functions-binning.R cwTools.R
############################################################
## centWave
##
## Some notes on a potential speed up:
## Tried:
## o initialize peaks matrix in the inner loop instead of rbind: slower.
## o pre-initialize the peaks list; slower.
## o keep the peaks matrix small, add additional columns only if fitgauss or
## verboseColumns is TRUE.
## Conclusion:
## o speed improvement can only come from internal methods called withihn.
##
#' @title Core API function for centWave peak detection
#'
#' @description This function performs peak density and wavelet based
#' chromatographic peak detection for high resolution LC/MS data in centroid
#' mode [Tautenhahn 2008].
#'
#' @details
#'
#' This algorithm is most suitable for high resolution
#' LC/\{TOF,OrbiTrap,FTICR\}-MS data in centroid mode. In the first phase
#' the method identifies \emph{regions of interest} (ROIs) representing
#' mass traces that are characterized as regions with less than \code{ppm}
#' m/z deviation in consecutive scans in the LC/MS map. In detail, starting
#' with a single m/z, a ROI is extended if a m/z can be found in the next scan
#' (spectrum) for which the difference to the mean m/z of the ROI is smaller
#' than the user defined \code{ppm} of the m/z. The mean m/z of the ROI is then
#' updated considering also the newly included m/z value.
#'
#' These ROIs are then, after some cleanup, analyzed using continuous wavelet
#' transform (CWT) to locate chromatographic peaks on different scales. The
#' first analysis step is skipped, if regions of interest are passed with
#' the \code{roiList} parameter.
#'
#' @note The \emph{centWave} was designed to work on centroided mode, thus it
#' is expected that such data is presented to the function.
#'
#' This function exposes core chromatographic peak detection functionality
#' of the \emph{centWave} method. While this function can be called
#' directly, users will generally call the corresponding method for the
#' data object instead.
#'
#' @param mz Numeric vector with the individual m/z values from all scans/
#' spectra of one file/sample.
#'
#' @param int Numeric vector with the individual intensity values from all
#' scans/spectra of one file/sample.
#'
#' @param scantime Numeric vector of length equal to the number of
#' spectra/scans of the data representing the retention time of each scan.
#'
#' @param valsPerSpect Numeric vector with the number of values for each
#' spectrum.
#'
#' @param sleep \code{numeric(1)} defining the number of seconds to wait between
#' iterations. Defaults to \code{sleep = 0}. If \code{> 0} a plot is
#' generated visualizing the identified chromatographic peak. Note: this
#' argument is for backward compatibility only and will be removed in
#' future.
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @family core peak detection functions
#'
#' @references
#' Ralf Tautenhahn, Christoph B\"{o}ttcher, and Steffen Neumann "Highly
#' sensitive feature detection for high resolution LC/MS"
#' \emph{BMC Bioinformatics} 2008, 9:504
#'
#' @return
#' A matrix, each row representing an identified chromatographic peak,
#' with columns:
#' \describe{
#'
#' \item{mz}{Intensity weighted mean of m/z values of the peak across
#' scans.}
#' \item{mzmin}{Minimum m/z of the peak.}
#' \item{mzmax}{Maximum m/z of the peak.}
#' \item{rt}{Retention time of the peak's midpoint.}
#' \item{rtmin}{Minimum retention time of the peak.}
#' \item{rtmax}{Maximum retention time of the peak.}
#' \item{into}{Integrated (original) intensity of the peak.}
#' \item{intb}{Per-peak baseline corrected integrated peak intensity.}
#' \item{maxo}{Maximum intensity of the peak.}
#' \item{sn}{Signal to noise ratio, defined as \code{(maxo - baseline)/sd},
#' \code{sd} being the standard deviation of local chromatographic noise.}
#' \item{egauss}{RMSE of Gaussian fit.}
#' }
#' Additional columns for \code{verboseColumns = TRUE}:
#' \describe{
#'
#' \item{mu}{Gaussian parameter mu.}
#' \item{sigma}{Gaussian parameter sigma.}
#' \item{h}{Gaussian parameter h.}
#' \item{f}{Region number of the m/z ROI where the peak was localized.}
#' \item{dppm}{m/z deviation of mass trace across scans in ppm.}
#' \item{scale}{Scale on which the peak was localized.}
#' \item{scpos}{Peak position found by wavelet analysis (scan number).}
#' \item{scmin}{Left peak limit found by wavelet analysis (scan number).}
#' \item{scmax}{Right peak limit found by wavelet analysis (scan numer).}
#' }
#'
#' @author Ralf Tautenhahn, Johannes Rainer
#'
#' @seealso \code{\link{centWave}} for the standard user interface method.
#'
#' @examples
#' ## Load the test file
#' data(faahko_sub)
#' ## Update the path to the files for the local system
#' dirname(faahko_sub) <- system.file("cdf/KO", package = "faahKO")
#'
#' ## Subset to one file and restrict to a certain retention time range
#' data <- filterRt(filterFile(faahko_sub, 1), c(2500, 3000))
#'
#' ## Get m/z and intensity values
#' mzs <- mz(data)
#' ints <- intensity(data)
#'
#' ## Define the values per spectrum:
#' valsPerSpect <- lengths(mzs)
#'
#' ## Calling the function. We're using a large value for noise and prefilter
#' ## to speed up the call in the example - in a real use case we would either
#' ## set the value to a reasonable value or use the default value.
#' res <- do_findChromPeaks_centWave(mz = unlist(mzs), int = unlist(ints),
#' scantime = rtime(data), valsPerSpect = valsPerSpect, noise = 10000,
#' prefilter = c(3, 10000))
#' head(res)
do_findChromPeaks_centWave <- function(mz, int, scantime, valsPerSpect,
ppm = 25,
peakwidth = c(20, 50),
snthresh = 10,
prefilter = c(3, 100),
mzCenterFun = "wMean",
integrate = 1,
mzdiff = -0.001,
fitgauss = FALSE,
noise = 0,
verboseColumns = FALSE,
roiList = list(),
firstBaselineCheck = TRUE,
roiScales = NULL,
sleep = 0,
extendLengthMSW = FALSE) {
if (getOption("originalCentWave", default = TRUE)) {
## message("DEBUG: using original centWave.")
.centWave_orig(mz = mz, int = int, scantime = scantime,
valsPerSpect = valsPerSpect, ppm = ppm, peakwidth = peakwidth,
snthresh = snthresh, prefilter = prefilter,
mzCenterFun = mzCenterFun, integrate = integrate,
mzdiff = mzdiff, fitgauss = fitgauss, noise = noise,
verboseColumns = verboseColumns, roiList = roiList,
firstBaselineCheck = firstBaselineCheck,
roiScales = roiScales, sleep = sleep,
extendLengthMSW = extendLengthMSW)
} else {
## message("DEBUG: using modified centWave.")
.centWave_new(mz = mz, int = int, scantime = scantime,
valsPerSpect = valsPerSpect, ppm = ppm, peakwidth = peakwidth,
snthresh = snthresh, prefilter = prefilter,
mzCenterFun = mzCenterFun, integrate = integrate,
mzdiff = mzdiff, fitgauss = fitgauss, noise = noise,
verboseColumns = verboseColumns, roiList = roiList,
firstBaselineCheck = firstBaselineCheck,
roiScales = roiScales, sleep = sleep)
}
}
############################################################
## ORIGINAL code from xcms_1.49.7
.centWave_orig <- function(mz, int, scantime, valsPerSpect,
ppm = 25, peakwidth = c(20,50), snthresh = 10,
prefilter = c(3,100), mzCenterFun = "wMean",
integrate = 1, mzdiff = -0.001, fitgauss = FALSE,
noise = 0, ## noise.local=TRUE,
sleep = 0, verboseColumns = FALSE, roiList = list(),
firstBaselineCheck = TRUE, roiScales = NULL,
extendLengthMSW = FALSE) {
## Input argument checking.
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if (length(mz) != length(int) | length(valsPerSpect) != length(scantime)
| length(mz) != sum(valsPerSpect))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
scanindex <- valueCount2ScanIndex(valsPerSpect) ## Get index vector for C calls
if (!is.double(mz))
mz <- as.double(mz)
if (!is.double(int))
int <- as.double(int)
## Fix the mzCenterFun
mzCenterFun <- paste("mzCenter",
gsub(mzCenterFun, pattern = "mzCenter.",
replacement = "", fixed = TRUE), sep=".")
if (!exists(mzCenterFun, mode="function"))
stop("Function '", mzCenterFun, "' not defined !")
if (!is.logical(firstBaselineCheck))
stop("Parameter 'firstBaselineCheck' should be logical!")
if (length(firstBaselineCheck) != 1)
stop("Parameter 'firstBaselineCheck' should be a single logical !")
if (length(roiScales) > 0)
if (length(roiScales) != length(roiList) | !is.numeric(roiScales))
stop("If provided, parameter 'roiScales' has to be a numeric with",
" length equal to the length of 'roiList'!")
## if (!is.null(roiScales)) {
## if (!is.numeric(roiScales) | length(roiScales) != length(roiList))
## stop("Parameter 'roiScales' has to be a numeric of length equal to",
## " parameter 'roiList'!")
##}
basenames <- c("mz", "mzmin", "mzmax", "rt", "rtmin", "rtmax",
"into", "intb", "maxo", "sn")
verbosenames <- c("egauss", "mu", "sigma", "h", "f", "dppm", "scale",
"scpos", "scmin", "scmax", "lmin", "lmax")
## Peak width: seconds to scales
scalerange <- round((peakwidth / mean(diff(scantime))) / 2)
if (length(z <- which(scalerange == 0)))
scalerange <- scalerange[-z]
if (length(scalerange) < 1) {
warning("No scales? Please check peak width!")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
return(invisible(nopeaks))
}
if (length(scalerange) > 1)
scales <- seq(from = scalerange[1], to = scalerange[2], by = 2)
else
scales <- scalerange
minPeakWidth <- scales[1]
noiserange <- c(minPeakWidth * 3, max(scales) * 3)
maxGaussOverlap <- 0.5
minPtsAboveBaseLine <- max(4, minPeakWidth - 2)
minCentroids <- minPtsAboveBaseLine
scRangeTol <- maxDescOutlier <- floor(minPeakWidth / 2)
scanrange <- c(1, length(scantime))
## If no ROIs are supplied then search for them.
if (length(roiList) == 0) {
message("Detecting mass traces at ", ppm, " ppm ... ", appendLF = FALSE)
## flush.console();
## We're including the findmzROI code in this function to reduce
## the need to copy objects etc.
## We could also sort the data by m/z anyway; wouldn't need that
## much time. Once we're using classes from MSnbase we can be
## sure that values are correctly sorted.
withRestarts(
tryCatch({
tmp <- capture.output(
roiList <- .Call("findmzROI",
mz, int, scanindex,
as.double(c(0.0, 0.0)),
as.integer(scanrange),
as.integer(length(scantime)),
as.double(ppm * 1e-6),
as.integer(minCentroids),
as.integer(prefilter),
as.integer(noise),
PACKAGE ='xcms' )
)
},
error = function(e){
if (grepl("m/z sort assumption violated !", e$message)) {
invokeRestart("fixSort")
} else {
simpleError(e)
}
}),
fixSort = function() {
## Force ordering of values within spectrum by mz:
## o split values into a list -> mz per spectrum, intensity per
## spectrum.
## o define the ordering.
## o re-order the mz and intensity and unlist again.
## Note: the Rle split is faster than the "conventional" factor split.
splitF <- Rle(1:length(valsPerSpect), valsPerSpect)
mzl <- as.list(S4Vectors::split(mz, f = splitF))
oidx <- lapply(mzl, order)
mz <<- unlist(mapply(mzl, oidx, FUN = function(y, z) {
return(y[z])
}, SIMPLIFY = FALSE, USE.NAMES = FALSE), use.names = FALSE)
int <<- unlist(mapply(as.list(split(int, f = splitF)), oidx,
FUN=function(y, z) {
return(y[z])
}, SIMPLIFY = FALSE, USE.NAMES = FALSE),
use.names = FALSE)
rm(mzl)
rm(splitF)
tmp <- capture.output(
roiList <<- .Call("findmzROI",
mz, int, scanindex,
as.double(c(0.0, 0.0)),
as.integer(scanrange),
as.integer(length(scantime)),
as.double(ppm * 1e-6),
as.integer(minCentroids),
as.integer(prefilter),
as.integer(noise),
PACKAGE ='xcms' )
)
}
)
message("OK")
## ROI.list <- findmzROI(object,scanrange=scanrange,dev=ppm * 1e-6,minCentroids=minCentroids, prefilter=prefilter, noise=noise)
if (length(roiList) == 0) {
warning("No ROIs found! \n")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
return(invisible(nopeaks))
}
}
## Second stage: process the ROIs
peaklist <- list()
Nscantime <- length(scantime)
lf <- length(roiList)
## cat('\n Detecting chromatographic peaks ... \n % finished: ')
## lp <- -1
message("Detecting chromatographic peaks in ", length(roiList),
" regions of interest ...", appendLF = FALSE)
for (f in 1:lf) {
## ## Show progress
## perc <- round((f/lf) * 100)
## if ((perc %% 10 == 0) && (perc != lp))
## {
## cat(perc," ",sep="");
## lp <- perc;
## }
## flush.console()
feat <- roiList[[f]]
N <- feat$scmax - feat$scmin + 1
peaks <- peakinfo <- NULL
mzrange <- c(feat$mzmin, feat$mzmax)
sccenter <- feat$scmin[1] + floor(N/2) - 1
scrange <- c(feat$scmin, feat$scmax)
## scrange + noiserange, used for baseline detection and wavelet analysis
sr <- c(max(scanrange[1], scrange[1] - max(noiserange)),
min(scanrange[2], scrange[2] + max(noiserange)))
eic <- .Call("getEIC", mz, int, scanindex, as.double(mzrange),
as.integer(sr), as.integer(length(scanindex)),
PACKAGE = "xcms")
## eic <- rawEIC(object,mzrange=mzrange,scanrange=sr)
d <- eic$intensity
td <- sr[1]:sr[2]
scan.range <- c(sr[1], sr[2])
## original mzROI range
idxs <- which(eic$scan %in% seq(scrange[1], scrange[2]))
mzROI.EIC <- list(scan=eic$scan[idxs], intensity=eic$intensity[idxs])
## mzROI.EIC <- rawEIC(object,mzrange=mzrange,scanrange=scrange)
omz <- .Call("getMZ", mz, int, scanindex, as.double(mzrange),
as.integer(scrange), as.integer(length(scantime)),
PACKAGE = 'xcms')
## omz <- rawMZ(object,mzrange=mzrange,scanrange=scrange)
if (all(omz == 0)) {
warning("centWave: no peaks found in ROI.")
next
}
od <- mzROI.EIC$intensity
otd <- mzROI.EIC$scan
if (all(od == 0)) {
warning("centWave: no peaks found in ROI.")
next
}
## scrange + scRangeTol, used for gauss fitting and continuous
## data above 1st baseline detection
ftd <- max(td[1], scrange[1] - scRangeTol) : min(td[length(td)],
scrange[2] + scRangeTol)
fd <- d[match(ftd, td)]
## 1st type of baseline: statistic approach
if (N >= 10*minPeakWidth) {
## in case of very long mass trace use full scan range
## for baseline detection
noised <- .Call("getEIC", mz, int, scanindex, as.double(mzrange),
as.integer(scanrange), as.integer(length(scanindex)),
PACKAGE="xcms")$intensity
## noised <- rawEIC(object,mzrange=mzrange,scanrange=scanrange)$intensity
} else {
noised <- d
}
## 90% trimmed mean as first baseline guess
noise <- estimateChromNoise(noised, trim = 0.05,
minPts = 3 * minPeakWidth)
## any continuous data above 1st baseline ?
if (firstBaselineCheck &
!continuousPtsAboveThreshold(fd, threshold = noise,
num = minPtsAboveBaseLine))
next
## 2nd baseline estimate using not-peak-range
lnoise <- getLocalNoiseEstimate(d, td, ftd, noiserange, Nscantime,
threshold = noise,
num = minPtsAboveBaseLine)
## Final baseline & Noise estimate
baseline <- max(1, min(lnoise[1], noise))
sdnoise <- max(1, lnoise[2])
sdthr <- sdnoise * snthresh
## is there any data above S/N * threshold ?
if (!(any(fd - baseline >= sdthr)))
next
wCoefs <- MSW.cwt(d, scales = scales, wavelet = 'mexh',
extendLengthMSW = extendLengthMSW)
if (!(!is.null(dim(wCoefs)) && any(wCoefs- baseline >= sdthr)))
next
if (td[length(td)] == Nscantime) ## workaround, localMax fails otherwise
wCoefs[nrow(wCoefs),] <- wCoefs[nrow(wCoefs) - 1, ] * 0.99
localMax <- MSW.getLocalMaximumCWT(wCoefs)
rL <- MSW.getRidge(localMax)
wpeaks <- sapply(rL,
function(x) {
w <- min(1:length(x),ncol(wCoefs))
any(wCoefs[x,w]- baseline >= sdthr)
})
if (any(wpeaks)) {
wpeaksidx <- which(wpeaks)
## check each peak in ridgeList
for (p in 1:length(wpeaksidx)) {
opp <- rL[[wpeaksidx[p]]]
pp <- unique(opp)
if (length(pp) >= 1) {
dv <- td[pp] %in% ftd
if (any(dv)) { ## peaks in orig. data range
## Final S/N check
if (any(d[pp[dv]]- baseline >= sdthr)) {
## if(!is.null(roiScales)) {
## allow roiScales to be a numeric of length 0
if(length(roiScales) > 0) {
## use given scale
best.scale.nr <- which(scales == roiScales[[f]])
if(best.scale.nr > length(opp))
best.scale.nr <- length(opp)
} else {
## try to decide which scale describes the peak best
inti <- numeric(length(opp))
irange <- rep(ceiling(scales[1]/2), length(opp))
for (k in 1:length(opp)) {
kpos <- opp[k]
r1 <- ifelse(kpos - irange[k] > 1,
kpos-irange[k], 1)
r2 <- ifelse(kpos + irange[k] < length(d),
kpos + irange[k], length(d))
inti[k] <- sum(d[r1:r2])
}
maxpi <- which.max(inti)
if (length(maxpi) > 1) {
m <- wCoefs[opp[maxpi], maxpi]
bestcol <- which(m == max(m),
arr.ind = TRUE)[2]
best.scale.nr <- maxpi[bestcol]
} else best.scale.nr <- maxpi
}
best.scale <- scales[best.scale.nr]
best.scale.pos <- opp[best.scale.nr]
pprange <- min(pp):max(pp)
## maxint <- max(d[pprange])
lwpos <- max(1,best.scale.pos - best.scale)
rwpos <- min(best.scale.pos + best.scale, length(td))
p1 <- match(td[lwpos], otd)[1]
p2 <- match(td[rwpos], otd)
p2 <- p2[length(p2)]
if (is.na(p1)) p1 <- 1
if (is.na(p2)) p2 <- N
mz.value <- omz[p1:p2]
mz.int <- od[p1:p2]
maxint <- max(mz.int)
## re-calculate m/z value for peak range
mzrange <- range(mz.value)
mzmean <- do.call(mzCenterFun,
list(mz = mz.value,
intensity = mz.int))
## Compute dppm only if needed
dppm <- NA
if (verboseColumns) {
if (length(mz.value) >= (minCentroids + 1)) {
dppm <- round(min(running(abs(diff(mz.value)) /
(mzrange[2] * 1e-6),
fun = max,
width = minCentroids)))
} else {
dppm <- round((mzrange[2] - mzrange[1]) /
(mzrange[2] * 1e-6))
}
}
peaks <- rbind(peaks,
c(mzmean,mzrange, ## mz
NA, NA, NA, ## rt, rtmin, rtmax,
NA, ## intensity (sum)
NA, ## intensity (-bl)
maxint, ## max intensity
round((maxint - baseline) / sdnoise), ## S/N Ratio
NA, ## Gaussian RMSE
NA,NA,NA, ## Gaussian Parameters
f, ## ROI Position
dppm, ## max. difference between the [minCentroids] peaks in ppm
best.scale, ## Scale
td[best.scale.pos],
td[lwpos],
td[rwpos], ## Peak positions guessed from the wavelet's (scan nr)
NA, NA)) ## Peak limits (scan nr)
peakinfo <- rbind(peakinfo,
c(best.scale, best.scale.nr,
best.scale.pos, lwpos, rwpos))
## Peak positions guessed from the wavelet's
}
}
}
} ##for
} ## if
## postprocessing
if (!is.null(peaks)) {
colnames(peaks) <- c(basenames, verbosenames)
colnames(peakinfo) <- c("scale", "scaleNr", "scpos",
"scmin", "scmax")
for (p in 1:dim(peaks)[1]) {
## find minima (peak boundaries), assign rt and intensity values
if (integrate == 1) {
lm <- descendMin(wCoefs[, peakinfo[p, "scaleNr"]],
istart = peakinfo[p, "scpos"])
gap <- all(d[lm[1]:lm[2]] == 0) # looks like we got stuck in a gap right in the middle of the peak
if ((lm[1] == lm[2]) || gap) # fall-back
lm <- descendMinTol(
d, startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
} else {
lm <- descendMinTol(d, startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
}
## Narrow peak rt boundaries by removing values below threshold
lm <- .narrow_rt_boundaries(lm, d)
lm_seq <- lm[1]:lm[2]
pd <- d[lm_seq]
peakrange <- td[lm]
peaks[p, "rtmin"] <- scantime[peakrange[1]]
peaks[p, "rtmax"] <- scantime[peakrange[2]]
peaks[p, "maxo"] <- max(pd)
pwid <- (scantime[peakrange[2]] - scantime[peakrange[1]]) /
(peakrange[2] - peakrange[1])
if (is.na(pwid))
pwid <- 1
peaks[p, "into"] <- pwid * sum(pd)
db <- pd - baseline
peaks[p, "intb"] <- pwid * sum(db[db > 0])
peaks[p, "lmin"] <- lm[1]
peaks[p, "lmax"] <- lm[2]
if (fitgauss) {
## perform gaussian fits, use wavelets for inital parameters
td_lm <- td[lm_seq]
md <- max(pd)
d1 <- pd / md ## normalize data for gaussian error calc.
pgauss <- fitGauss(td_lm, pd,
pgauss = list(mu = peaks[p, "scpos"],
sigma = peaks[p, "scmax"] -
peaks[p, "scmin"],
h = peaks[p, "maxo"]))
rtime <- peaks[p, "scpos"]
if (!any(is.na(pgauss)) && all(pgauss > 0)) {
gtime <- td[match(round(pgauss$mu), td)]
if (!is.na(gtime)) {
rtime <- gtime
peaks[p, "mu"] <- pgauss$mu
peaks[p, "sigma"] <- pgauss$sigma
peaks[p, "h"] <- pgauss$h
peaks[p,"egauss"] <- sqrt(
(1 / length(td_lm)) *
sum(((d1 - gauss(td_lm, pgauss$h / md,
pgauss$mu, pgauss$sigma))^2)))
}
}
peaks[p, "rt"] <- scantime[rtime]
## avoid fitting side effects
if (peaks[p, "rt"] < peaks[p, "rtmin"])
peaks[p, "rt"] <- scantime[peaks[p, "scpos"]]
} else
peaks[p, "rt"] <- scantime[peaks[p, "scpos"]]
}
peaks <- joinOverlappingPeaks(td, d, otd, omz, od, scantime,
scan.range, peaks, maxGaussOverlap,
mzCenterFun = mzCenterFun)
}
## BEGIN - plotting/sleep
if ((sleep >0) && (!is.null(peaks))) {
tdp <- scantime[td]; trange <- range(tdp)
egauss <- paste(round(peaks[,"egauss"],3),collapse=", ")
cdppm <- paste(peaks[,"dppm"],collapse=", ")
csn <- paste(peaks[,"sn"],collapse=", ")
par(bg = "white")
l <- layout(matrix(c(1,2,3),nrow=3,ncol=1,byrow=T),heights=c(.5,.75,2));
par(mar= c(2, 4, 4, 2) + 0.1)
## plotRaw(object,mzrange=mzrange,rtrange=trange,log=TRUE,title='')
## Do plotRaw manually.
raw_mat <- .rawMat(mz = mz, int = int, scantime = scantime,
valsPerSpect = valsPerSpect, mzrange = mzrange,
rtrange = rtrange, log = TRUE)
if (nrow(raw_mat) > 0) {
y <- raw_mat[, "intensity"]
ylim <- range(y)
y <- y / ylim[2]
colorlut <- terrain.colors(16)
col <- colorlut[y * 15 + 1]
plot(raw_mat[, "time"], raw_mat[, "mz"], pch = 20, cex = .5,
main = "", xlab = "Seconds", ylab = "m/z", col = col,
xlim = trange)
} else {
plot(c(NA, NA), main = "", xlab = "Seconds", ylab = "m/z",
xlim = trange, ylim = mzrange)
}
## done
title(main=paste(f,': ', round(mzrange[1],4),' - ',round(mzrange[2],4),' m/z , dppm=',cdppm,', EGauss=',egauss ,', S/N =',csn,sep=''))
par(mar= c(1, 4, 1, 2) + 0.1)
image(y=scales[1:(dim(wCoefs)[2])],z=wCoefs,col=terrain.colors(256),xaxt='n',ylab='CWT coeff.')
par(mar= c(4, 4, 1, 2) + 0.1)
plot(tdp,d,ylab='Intensity',xlab='Scan Time');lines(tdp,d,lty=2)
lines(scantime[otd],od,lty=2,col='blue') ## original mzbox range
abline(h=baseline,col='green')
bwh <- length(sr[1]:sr[2]) - length(baseline)
if (odd(bwh)) {bwh1 <- floor(bwh/2); bwh2 <- bwh1+1} else {bwh1<-bwh2<-bwh/2}
if (any(!is.na(peaks[,"scpos"])))
{ ## plot centers and width found through wavelet analysis
abline(v=scantime[na.omit(peaks[(peaks[,"scpos"] >0),"scpos"])],col='red')
}
abline(v=na.omit(c(peaks[,"rtmin"],peaks[,"rtmax"])),col='green',lwd=1)
if (fitgauss) {
tdx <- seq(min(td),max(td),length.out=200)
tdxp <- seq(trange[1],trange[2],length.out=200)
fitted.peaks <- which(!is.na(peaks[,"mu"]))
for (p in fitted.peaks)
{ ## plot gaussian fits
yg<-gauss(tdx,peaks[p,"h"],peaks[p,"mu"],peaks[p,"sigma"])
lines(tdxp,yg,col='blue')
}
}
Sys.sleep(sleep)
}
## -- END plotting/sleep
if (!is.null(peaks)) {
peaklist[[length(peaklist) + 1]] <- peaks
}
} ## f
if (length(peaklist) == 0) {
warning("No peaks found!")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
message(" FAIL: none found!")
return(nopeaks)
}
p <- do.call(rbind, peaklist)
if (!verboseColumns)
p <- p[, basenames, drop = FALSE]
uorder <- order(p[, "into"], decreasing = TRUE)
pm <- as.matrix(p[,c("mzmin", "mzmax", "rtmin", "rtmax"), drop = FALSE])
uindex <- rectUnique(pm, uorder, mzdiff, ydiff = -0.00001) ## allow adjacent peaks
pr <- p[uindex, , drop = FALSE]
message(" OK: ", nrow(pr), " found.")
return(pr)
}
## This version fixes issue #135, i.e. that the peak signal is integrated based
## on the mzrange of the ROI and not of the actually reported peak.
## Issue #136.
##
## What's different to the original version?
##
## 1) The mz range of the peaks is calculated only using mz values with a
## measured intensity. This avoids mz ranges from 0 to max mz of the peak,
## with the mz=0 corresponding actually to scans in which no intensity was
## measured. Search for "@MOD1" to jump to the respective code.
##
## 2) The intensities for the peak are reloaded with the refined mz range during
## the postprocessing. Search for "@MOD2" to jump to the respective code.
##
## What I don't like:
## o Might be better if the getEIC and getMZ C functions returned NA instead of 0
## if nothing was measured.
## o The joinOverlappingPeaks is still calculated using the variable "d" which
## contains all intensities from the ROI - might actually not be too bad
## though.
.centWave_new <- function(mz, int, scantime, valsPerSpect,
ppm = 25, peakwidth = c(20,50), snthresh = 10,
prefilter = c(3,100), mzCenterFun = "wMean",
integrate = 1, mzdiff = -0.001, fitgauss = FALSE,
noise = 0, ## noise.local=TRUE,
sleep = 0, verboseColumns = FALSE, roiList = list(),
firstBaselineCheck = TRUE, roiScales = NULL) {
if (sleep)
warning("Parameter 'sleep' is defunct")
## Input argument checking.
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if (length(mz) != length(int) | length(valsPerSpect) != length(scantime)
| length(mz) != sum(valsPerSpect))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
scanindex <- valueCount2ScanIndex(valsPerSpect) ## Get index vector for C calls
if (!is.double(mz))
mz <- as.double(mz)
if (!is.double(int))
int <- as.double(int)
## Fix the mzCenterFun
mzCenterFun <- paste("mzCenter",
gsub(mzCenterFun, pattern = "mzCenter.",
replacement = "", fixed = TRUE), sep=".")
if (!exists(mzCenterFun, mode="function"))
stop("Function '", mzCenterFun, "' not defined !")
if (!is.logical(firstBaselineCheck))
stop("Parameter 'firstBaselineCheck' should be logical!")
if (length(firstBaselineCheck) != 1)
stop("Parameter 'firstBaselineCheck' should be a single logical !")
if (length(roiScales) > 0)
if (length(roiScales) != length(roiList) | !is.numeric(roiScales))
stop("If provided, parameter 'roiScales' has to be a numeric with",
" length equal to the length of 'roiList'!")
basenames <- c("mz", "mzmin", "mzmax", "rt", "rtmin", "rtmax",
"into", "intb", "maxo", "sn")
verbosenames <- c("egauss", "mu", "sigma", "h", "f", "dppm", "scale",
"scpos", "scmin", "scmax", "lmin", "lmax")
## Peak width: seconds to scales
scalerange <- round((peakwidth / mean(diff(scantime))) / 2)
if (length(z <- which(scalerange == 0)))
scalerange <- scalerange[-z]
if (length(scalerange) < 1) {
warning("No scales? Please check peak width!")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
return(invisible(nopeaks))
}
if (length(scalerange) > 1)
scales <- seq(from = scalerange[1], to = scalerange[2], by = 2)
else
scales <- scalerange
minPeakWidth <- scales[1]
noiserange <- c(minPeakWidth * 3, max(scales) * 3)
maxGaussOverlap <- 0.5
minPtsAboveBaseLine <- max(4, minPeakWidth - 2)
minCentroids <- minPtsAboveBaseLine
scRangeTol <- maxDescOutlier <- floor(minPeakWidth / 2)
scanrange <- c(1, length(scantime))
## If no ROIs are supplied then search for them.
if (length(roiList) == 0) {
message("Detecting mass traces at ", ppm, " ppm ... ", appendLF = FALSE)
## flush.console();
## We're including the findmzROI code in this function to reduce
## the need to copy objects etc.
## We could also sort the data by m/z anyway; wouldn't need that
## much time. Once we're using classes from MSnbase we can be
## sure that values are correctly sorted.
withRestarts(
tryCatch({
tmp <- capture.output(
roiList <- .Call("findmzROI",
mz, int, scanindex,
as.double(c(0.0, 0.0)),
as.integer(scanrange),
as.integer(length(scantime)),
as.double(ppm * 1e-6),
as.integer(minCentroids),
as.integer(prefilter),
as.integer(noise),
PACKAGE ='xcms' )
)
},
error = function(e){
if (grepl("m/z sort assumption violated !", e$message)) {
invokeRestart("fixSort")
} else {
simpleError(e)
}
}),
fixSort = function() {
## Force ordering of values within spectrum by mz:
## o split values into a list -> mz per spectrum, intensity per
## spectrum.
## o define the ordering.
## o re-order the mz and intensity and unlist again.
## Note: the Rle split is faster than the "conventional" factor split.
splitF <- Rle(1:length(valsPerSpect), valsPerSpect)
mzl <- as.list(S4Vectors::split(mz, f = splitF))
oidx <- lapply(mzl, order)
mz <<- unlist(mapply(mzl, oidx, FUN = function(y, z) {
return(y[z])
}, SIMPLIFY = FALSE, USE.NAMES = FALSE), use.names = FALSE)
int <<- unlist(mapply(as.list(split(int, f = splitF)), oidx,
FUN=function(y, z) {
return(y[z])
}, SIMPLIFY = FALSE, USE.NAMES = FALSE),
use.names = FALSE)
rm(mzl)
rm(splitF)
tmp <- capture.output(
roiList <<- .Call("findmzROI",
mz, int, scanindex,
as.double(c(0.0, 0.0)),
as.integer(scanrange),
as.integer(length(scantime)),
as.double(ppm * 1e-6),
as.integer(minCentroids),
as.integer(prefilter),
as.integer(noise),
PACKAGE ='xcms' )
)
}
)
message("OK")
if (length(roiList) == 0) {
warning("No ROIs found! \n")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
return(invisible(nopeaks))
}
}
## Second stage: process the ROIs
peaklist <- list()
Nscantime <- length(scantime)
lf <- length(roiList)
## cat('\n Detecting chromatographic peaks ... \n % finished: ')
## lp <- -1
message("Detecting chromatographic peaks in ", length(roiList),
" regions of interest ...", appendLF = FALSE)
for (f in 1:lf) {
## cat("\nProcess roi ", f, "\n")
feat <- roiList[[f]]
N <- feat$scmax - feat$scmin + 1
peaks <- peakinfo <- NULL
mzrange <- c(feat$mzmin, feat$mzmax)
mzrange_ROI <- mzrange
sccenter <- feat$scmin[1] + floor(N/2) - 1
scrange <- c(feat$scmin, feat$scmax)
## scrange + noiserange, used for baseline detection and wavelet analysis
sr <- c(max(scanrange[1], scrange[1] - max(noiserange)),
min(scanrange[2], scrange[2] + max(noiserange)))
eic <- .Call("getEIC", mz, int, scanindex, as.double(mzrange),
as.integer(sr), as.integer(length(scanindex)),
PACKAGE = "xcms")
d <- eic$intensity
td <- sr[1]:sr[2]
scan.range <- c(sr[1], sr[2])
## original mzROI range
idxs <- which(eic$scan %in% seq(scrange[1], scrange[2]))
mzROI.EIC <- list(scan=eic$scan[idxs], intensity=eic$intensity[idxs])
omz <- .Call("getMZ", mz, int, scanindex, as.double(mzrange),
as.integer(scrange), as.integer(length(scantime)),
PACKAGE = 'xcms')
if (all(omz == 0)) {
warning("centWave: no peaks found in ROI.")
next
}
od <- mzROI.EIC$intensity
otd <- mzROI.EIC$scan
if (all(od == 0)) {
warning("centWave: no peaks found in ROI.")
next
}
## scrange + scRangeTol, used for gauss fitting and continuous
## data above 1st baseline detection
ftd <- max(td[1], scrange[1] - scRangeTol) : min(td[length(td)],
scrange[2] + scRangeTol)
fd <- d[match(ftd, td)]
## 1st type of baseline: statistic approach
if (N >= 10 * minPeakWidth) {
## in case of very long mass trace use full scan range
## for baseline detection
noised <- .Call("getEIC", mz, int, scanindex, as.double(mzrange),
as.integer(scanrange), as.integer(length(scanindex)),
PACKAGE="xcms")$intensity
} else {
noised <- d
}
## 90% trimmed mean as first baseline guess
noise <- estimateChromNoise(noised, trim = 0.05,
minPts = 3 * minPeakWidth)
## any continuous data above 1st baseline ?
if (firstBaselineCheck &
!continuousPtsAboveThreshold(fd, threshold = noise,
num = minPtsAboveBaseLine))
next
## 2nd baseline estimate using not-peak-range
lnoise <- getLocalNoiseEstimate(d, td, ftd, noiserange, Nscantime,
threshold = noise,
num = minPtsAboveBaseLine)
## Final baseline & Noise estimate
baseline <- max(1, min(lnoise[1], noise))
sdnoise <- max(1, lnoise[2])
sdthr <- sdnoise * snthresh
## is there any data above S/N * threshold ?
if (!(any(fd - baseline >= sdthr)))
next
wCoefs <- MSW.cwt(d, scales = scales, wavelet = 'mexh')
if (!(!is.null(dim(wCoefs)) && any(wCoefs- baseline >= sdthr)))
next
if (td[length(td)] == Nscantime) ## workaround, localMax fails otherwise
wCoefs[nrow(wCoefs),] <- wCoefs[nrow(wCoefs) - 1, ] * 0.99
localMax <- MSW.getLocalMaximumCWT(wCoefs)
rL <- MSW.getRidge(localMax)
wpeaks <- sapply(rL,
function(x) {
w <- min(1:length(x),ncol(wCoefs))
any(wCoefs[x,w]- baseline >= sdthr)
})
if (any(wpeaks)) {
wpeaksidx <- which(wpeaks)
## check each peak in ridgeList
for (p in 1:length(wpeaksidx)) {
opp <- rL[[wpeaksidx[p]]]
pp <- unique(opp)
if (length(pp) >= 1) {
dv <- td[pp] %in% ftd
if (any(dv)) { ## peaks in orig. data range
## Final S/N check
if (any(d[pp[dv]]- baseline >= sdthr)) {
## if(!is.null(roiScales)) {
## allow roiScales to be a numeric of length 0
if(length(roiScales) > 0) {
## use given scale
best.scale.nr <- which(scales == roiScales[[f]])
if(best.scale.nr > length(opp))
best.scale.nr <- length(opp)
} else {
## try to decide which scale describes the peak best
inti <- numeric(length(opp))
irange <- rep(ceiling(scales[1]/2), length(opp))
for (k in 1:length(opp)) {
kpos <- opp[k]
r1 <- ifelse(kpos - irange[k] > 1,
kpos-irange[k], 1)
r2 <- ifelse(kpos + irange[k] < length(d),
kpos + irange[k], length(d))
inti[k] <- sum(d[r1:r2])
}
maxpi <- which.max(inti)
if (length(maxpi) > 1) {
m <- wCoefs[opp[maxpi], maxpi]
bestcol <- which(m == max(m),
arr.ind = TRUE)[2]
best.scale.nr <- maxpi[bestcol]
} else best.scale.nr <- maxpi
}
best.scale <- scales[best.scale.nr]
best.scale.pos <- opp[best.scale.nr]
pprange <- min(pp):max(pp)
## maxint <- max(d[pprange])
lwpos <- max(1,best.scale.pos - best.scale)
rwpos <- min(best.scale.pos + best.scale, length(td))
p1 <- match(td[lwpos], otd)[1]
p2 <- match(td[rwpos], otd)
p2 <- p2[length(p2)]
## cat("p1: ", p1, " p2: ", p2, "\n")
if (is.na(p1)) p1 <- 1
if (is.na(p2)) p2 <- N
mz.value <- omz[p1:p2]
## cat("mz.value: ", paste0(mz.value, collapse = ", "),
## "\n")
mz.int <- od[p1:p2]
maxint <- max(mz.int)
## @MOD1: Remove mz values for which no intensity was
## measured. Would be better if getEIC returned NA
## if nothing was measured.
mzorig <- mz.value
mz.value <- mz.value[mz.int > 0]
mz.int <- mz.int[mz.int > 0]
## Call next to avoid reporting peaks without mz
## values (issue #165).
if (length(mz.value) == 0)
next
## cat("mz.value: ", paste0(mz.value, collapse = ", "),
## "\n")
## re-calculate m/z value for peak range
## cat("mzrange refined: [",
## paste0(mzrange, collapse = ", "), "]")
## hm, shouldn't we get rid of the mz = 0 here?
mzrange <- range(mz.value)
## cat(" -> [",
## paste0(mzrange, collapse = ", "), "]\n")
mzmean <- do.call(mzCenterFun,
list(mz = mz.value,
intensity = mz.int))
## Compute dppm only if needed
dppm <- NA
if (verboseColumns) {
if (length(mz.value) >= (minCentroids + 1)) {
dppm <- round(min(running(abs(diff(mz.value)) /
(mzrange[2] * 1e-6),
fun = max,
width = minCentroids)))
} else {
dppm <- round((mzrange[2] - mzrange[1]) /
(mzrange[2] * 1e-6))
}
}
peaks <- rbind(peaks,
c(mzmean,mzrange, ## mz
NA, NA, NA, ## rt, rtmin, rtmax,
NA, ## intensity (sum)
NA, ## intensity (-bl)
maxint, ## max intensity
round((maxint - baseline) / sdnoise), ## S/N Ratio
NA, ## Gaussian RMSE
NA,NA,NA, ## Gaussian Parameters
f, ## ROI Position
dppm, ## max. difference between the [minCentroids] peaks in ppm
best.scale, ## Scale
td[best.scale.pos],
td[lwpos],
td[rwpos], ## Peak positions guessed from the wavelet's (scan nr)
NA, NA)) ## Peak limits (scan nr)
peakinfo <- rbind(peakinfo,
c(best.scale, best.scale.nr,
best.scale.pos, lwpos, rwpos))
## Peak positions guessed from the wavelet's
}
}
}
} ##for
} ## if
## postprocessing
if (!is.null(peaks)) {
colnames(peaks) <- c(basenames, verbosenames)
colnames(peakinfo) <- c("scale", "scaleNr", "scpos",
"scmin", "scmax")
for (p in 1:dim(peaks)[1]) {
## @MOD2
## Fix for issue #135: reload the EIC data if the
## mzrange differs from that of the ROI, but only if the mz
## range of the peak is different from the one of the ROI.
mzr <- peaks[p, c("mzmin", "mzmax")]
if (any(mzr != mzrange_ROI)) {
eic <- .Call("getEIC", mz, int, scanindex,
as.double(mzr), as.integer(sr),
as.integer(length(scanindex)),
PACKAGE = "xcms")
current_ints <- eic$intensity
## Force re-loading also of a potential additional peak in
## the same ROI.
mzrange_ROI <- c(0, 0)
} else {
current_ints <- d
}
## find minima, assign rt and intensity values
if (integrate == 1) {
lm <- descendMin(wCoefs[, peakinfo[p,"scaleNr"]],
istart = peakinfo[p,"scpos"])
gap <- all(current_ints[lm[1]:lm[2]] == 0) ## looks like we got stuck in a gap right in the middle of the peak
if ((lm[1] == lm[2]) || gap )## fall-back
lm <- descendMinTol(current_ints,
startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
} else {
lm <- descendMinTol(current_ints,
startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
}
## Narrow peak rt boundaries by removing values below cut-off
lm <- .narrow_rt_boundaries(lm, d)
lm_seq <- lm[1]:lm[2]
pd <- current_ints[lm_seq]
peakrange <- td[lm]
peaks[p, "rtmin"] <- scantime[peakrange[1]]
peaks[p, "rtmax"] <- scantime[peakrange[2]]
peaks[p, "maxo"] <- max(pd)
pwid <- (scantime[peakrange[2]] - scantime[peakrange[1]]) /
(peakrange[2] - peakrange[1])
if (is.na(pwid))
pwid <- 1
peaks[p, "into"] <- pwid * sum(pd)
db <- pd - baseline
peaks[p, "intb"] <- pwid * sum(db[db > 0])
peaks[p, "lmin"] <- lm[1]
peaks[p, "lmax"] <- lm[2]
if (fitgauss) {
## perform gaussian fits, use wavelets for inital parameters
td_lm <- td[lm_seq]
md <- max(pd)
d1 <- pd / md ## normalize data for gaussian error calc.
pgauss <- fitGauss(td_lm, pd,
pgauss = list(mu = peaks[p, "scpos"],
sigma = peaks[p, "scmax"] -
peaks[p, "scmin"],
h = peaks[p, "maxo"]))
rtime <- peaks[p, "scpos"]
if (!any(is.na(pgauss)) && all(pgauss > 0)) {
gtime <- td[match(round(pgauss$mu), td)]
if (!is.na(gtime)) {
rtime <- gtime
peaks[p, "mu"] <- pgauss$mu
peaks[p, "sigma"] <- pgauss$sigma
peaks[p, "h"] <- pgauss$h
peaks[p,"egauss"] <- sqrt(
(1 / length(td_lm)) *
sum(((d1 - gauss(td_lm, pgauss$h / md,
pgauss$mu, pgauss$sigma))^2)))
}
}
peaks[p, "rt"] <- scantime[rtime]
## avoid fitting side effects
if (peaks[p, "rt"] < peaks[p, "rtmin"])
peaks[p, "rt"] <- scantime[peaks[p, "scpos"]]
} else
peaks[p, "rt"] <- scantime[peaks[p, "scpos"]]
}
## Use d here instead of current_ints
peaks <- joinOverlappingPeaks(td, d, otd, omz, od,
scantime, scan.range, peaks,
maxGaussOverlap,
mzCenterFun = mzCenterFun)
}
if (!is.null(peaks)) {
peaklist[[length(peaklist) + 1]] <- peaks
}
} ## f
if (length(peaklist) == 0) {
warning("No peaks found!")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
message(" FAIL: none found!")
return(nopeaks)
}
## cat("length peaklist: ", length(peaklist), "\n")
p <- do.call(rbind, peaklist)
if (!verboseColumns)
p <- p[, basenames, drop = FALSE]
return(p)
uorder <- order(p[, "into"], decreasing = TRUE)
pm <- as.matrix(p[,c("mzmin", "mzmax", "rtmin", "rtmax"), drop = FALSE])
uindex <- rectUnique(pm, uorder, mzdiff, ydiff = -0.00001) ## allow adjacent peaks
pr <- p[uindex, , drop = FALSE]
message(" OK: ", nrow(pr), " found.")
return(pr)
}
############################################################
## massifquant
##
#' @title Core API function for massifquant peak detection
#'
#' @description Massifquant is a Kalman filter (KF)-based chromatographic peak
#' detection for XC-MS data in centroid mode. The identified peaks
#' can be further refined with the \emph{centWave} method (see
#' \code{\link{do_findChromPeaks_centWave}} for details on centWave)
#' by specifying \code{withWave = TRUE}.
#'
#' @details This algorithm's performance has been tested rigorously
#' on high resolution LC/{OrbiTrap, TOF}-MS data in centroid mode.
#' Simultaneous kalman filters identify peaks and calculate their
#' area under the curve. The default parameters are set to operate on
#' a complex LC-MS Orbitrap sample. Users will find it useful to do some
#' simple exploratory data analysis to find out where to set a minimum
#' intensity, and identify how many scans an average peak spans. The
#' \code{consecMissedLimit} parameter has yielded good performance on
#' Orbitrap data when set to (\code{2}) and on TOF data it was found best
#' to be at (\code{1}). This may change as the algorithm has yet to be
#' tested on many samples. The \code{criticalValue} parameter is perhaps
#' most dificult to dial in appropriately and visual inspection of peak
#' identification is the best suggested tool for quick optimization.
#' The \code{ppm} and \code{checkBack} parameters have shown less influence
#' than the other parameters and exist to give users flexibility and
#' better accuracy.
#'
#' @inheritParams do_findChromPeaks_centWave
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @inheritParams findChromPeaks-massifquant
#'
#' @return
#' A matrix, each row representing an identified chromatographic peak,
#' with columns:
#' \describe{
#' \item{mz}{Intensity weighted mean of m/z values of the peaks across
#' scans.}
#' \item{mzmin}{Minumum m/z of the peak.}
#' \item{mzmax}{Maximum m/z of the peak.}
#' \item{rtmin}{Minimum retention time of the peak.}
#' \item{rtmax}{Maximum retention time of the peak.}
#' \item{rt}{Retention time of the peak's midpoint.}
#' \item{into}{Integrated (original) intensity of the peak.}
#' \item{maxo}{Maximum intensity of the peak.}
#' }
#'
#' If \code{withWave} is set to \code{TRUE}, the result is the same as
#' returned by the \code{\link{do_findChromPeaks_centWave}} method.
#'
#' @family core peak detection functions
#'
#' @seealso \code{\link{massifquant}} for the standard user interface method.
#'
#' @references
#' Conley CJ, Smith R, Torgrip RJ, Taylor RM, Tautenhahn R and Prince JT
#' "Massifquant: open-source Kalman filter-based XC-MS isotope trace feature
#' detection" \emph{Bioinformatics} 2014, 30(18):2636-43.
#'
#' @author Christopher Conley
#'
#' @examples
#'
#' ## Load the test file
#' data(faahko_sub)
#' ## Update the path to the files for the local system
#' dirname(faahko_sub) <- system.file("cdf/KO", package = "faahKO")
#'
#' ## Subset to one file and restrict to a certain retention time range
#' data <- filterRt(filterFile(faahko_sub, 1), c(2500, 3000))
#'
#' ## Get m/z and intensity values
#' mzs <- mz(data)
#' ints <- intensity(data)
#'
#' ## Define the values per spectrum:
#' valsPerSpect <- lengths(mzs)
#'
#' ## Perform the peak detection using massifquant - setting prefilter to
#' ## a high value to speed up the call for the example
#' res <- do_findChromPeaks_massifquant(mz = unlist(mzs), int = unlist(ints),
#' scantime = rtime(data), valsPerSpect = valsPerSpect,
#' prefilter = c(3, 10000))
#' head(res)
do_findChromPeaks_massifquant <- function(mz,
int,
scantime,
valsPerSpect,
ppm = 10,
peakwidth = c(20, 50),
snthresh = 10,
prefilter = c(3, 100),
mzCenterFun = "wMean",
integrate = 1,
mzdiff = -0.001,
fitgauss = FALSE,
noise = 0,
verboseColumns = FALSE,
criticalValue = 1.125,
consecMissedLimit = 2,
unions = 1,
checkBack = 0,
withWave = FALSE) {
message("\n Massifquant, Copyright (C) 2013 Brigham Young University.")
message(" Massifquant comes with ABSOLUTELY NO WARRANTY.",
" See LICENSE for details.", sep ="")
## flush.console()
## TODO @jo Ensure in upstream method that data is in centroided mode!
## TODO @jo Ensure the upstream method did eventual sub-setting on scanrange
## Input argument checking.
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if ((length(mz) != length(int)) | (length(valsPerSpect) != length(scantime))
| (length(mz) != sum(valsPerSpect)))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
if (!is.double(mz))
mz <- as.double(mz)
if (!is.double(int))
int <- as.double(int)
## Fix the mzCenterFun
mzCenterFun <- paste("mzCenter",
gsub(mzCenterFun, pattern = "mzCenter.",
replacement = "", fixed = TRUE), sep=".")
if (!exists(mzCenterFun, mode="function"))
stop("Error: >", mzCenterFun, "< not defined !")
message("\n Detecting mass traces at ",ppm,"ppm ... ", appendLF = FALSE)
flush.console()
massifquantROIs <- do_findKalmanROI(mz = mz, int = int, scantime = scantime,
valsPerSpect = valsPerSpect,
minIntensity = prefilter[2],
minCentroids = peakwidth[1],
criticalVal = criticalValue,
consecMissedLim = consecMissedLimit,
segs = unions, scanBack = checkBack,
ppm = ppm)
message("OK")
if (withWave) {
featlist <- do_findChromPeaks_centWave(mz = mz, int = int,
scantime = scantime,
valsPerSpect = valsPerSpect,
ppm = ppm, peakwidth = peakwidth,
snthresh = snthresh,
prefilter = prefilter,
mzCenterFun = mzCenterFun,
integrate = integrate,
mzdiff = mzdiff,
fitgauss = fitgauss,
noise = noise,
verboseColumns = verboseColumns,
roiList = massifquantROIs)
}
else {
## Get index vector for C calls
scanindex <- valueCount2ScanIndex(valsPerSpect)
basenames <- c("mz","mzmin","mzmax","rtmin","rtmax","rt", "into")
if (length(massifquantROIs) == 0) {
warning("\nNo peaks found!")
nopeaks <- matrix(nrow=0, ncol=length(basenames))
colnames(nopeaks) <- basenames
return(nopeaks)
}
## Get the max intensity for each peak.
maxo <- lapply(massifquantROIs, function(z) {
raw <- .rawMat(mz = mz, int = int, scantime = scantime,
valsPerSpect = valsPerSpect,
mzrange = c(z$mzmin, z$mzmax),
scanrange = c(z$scmin, z$scmax))
max(raw[, 3])
})
## p <- t(sapply(massifquantROIs, unlist))
p <- do.call(rbind, lapply(massifquantROIs, unlist, use.names = FALSE))
colnames(p) <- basenames
p <- cbind(p, maxo = unlist(maxo))
#calculate median index
p[, "rt"] <- as.integer(p[, "rtmin"] + ( (p[, "rt"] + 1) / 2 ) - 1)
#convert from index into actual time
p[, "rtmin"] <- scantime[p[, "rtmin"]]
p[, "rtmax"] <- scantime[p[, "rtmax"]]
p[, "rt"] <- scantime[p[, "rt"]]
uorder <- order(p[, "into"], decreasing = TRUE)
pm <- as.matrix(p[, c("mzmin", "mzmax", "rtmin", "rtmax"),
drop = FALSE])
uindex <- rectUnique(pm, uorder, mzdiff, ydiff = -0.00001) ## allow adjacent peaks;
featlist <- p[uindex, , drop = FALSE]
message(" ", dim(featlist)[1]," Peaks.");
return(featlist)
}
return(featlist)
}
## The version of matchedFilter:
## .matchedFilter_orig: original code, iterative buffer creation.
## .matchedFilter_binYonX_iter: iterative buffer creation but using our binning function.
## .matchedFilter_no_iter: original binning, but a single binning call.
## .matchedFilter_binYonX_no_iter: single binning call using our binning function.
############################################################
## matchedFilter
##
## That's the function that matches the code from the
## findPeaks.matchedFilter method from the xcms package.
## The peak detection is performed on the binned data. Depending on the variable
## `bufsize` the function iteratively bins the intensity values on m/z dimension into
## bins of size `step` always binning into `bufsize` bins. While ensuring low memory
## usage, this iterative buffering is actually quite time consuming.
## The loop runs over the variable `mass` which corresponds to the midpoints of the
## bins. Peak detection is performed for bin `i` considering also `steps` neighboring
## bins. As detailed above, if the index i is outside of the buffer size, the binnin
## is performed for the next chunk of `bufsize` bins.
##
## This function takes basic R-objects and might thus be used as the base analysis
## method for a future xcms API.
## mz is a numeric vector with all m/z values.
## int is a numeric vector with the intensities.
## valsPerSpect: is an integer vector with the number of values per spectrum.
## This will be converted to what xcms calls the scanindex.
## TODO: in the long run it would be better to avoid buffer creation, extending,
## filling and all this stuff being done in a for loop.
## impute: none (=bin), binlin, binlinbase, intlin
## baseValue default: min(int)/2 (smallest value in the whole data set).
##
#' @title Core API function for matchedFilter peak detection
#'
#' @description This function identifies peaks in the chromatographic
#' time domain as described in [Smith 2006]. The intensity values are
#' binned by cutting The LC/MS data into slices (bins) of a mass unit
#' (\code{binSize} m/z) wide. Within each bin the maximal intensity is
#' selected. The peak detection is then performed in each bin by
#' extending it based on the \code{steps} parameter to generate slices
#' comprising bins \code{current_bin - steps +1} to
#' \code{current_bin + steps - 1}.
#' Each of these slices is then filtered with matched filtration using
#' a second-derative Gaussian as the model peak shape. After filtration
#' peaks are detected using a signal-to-ration cut-off. For more details
#' and illustrations see [Smith 2006].
#'
#' @details The intensities are binned by the provided m/z values within each
#' spectrum (scan). Binning is performed such that the bins are centered
#' around the m/z values (i.e. the first bin includes all m/z values between
#' \code{min(mz) - bin_size/2} and \code{min(mz) + bin_size/2}).
#'
#' For more details on binning and missing value imputation see
#' \code{\link{binYonX}} and \code{\link{imputeLinInterpol}} methods.
#'
#' @note This function exposes core peak detection functionality of
#' the \emph{matchedFilter} method. While this function can be called
#' directly, users will generally call the corresponding method for the
#' data object instead (e.g. the \code{link{findPeaks.matchedFilter}}
#' method).
#'
#' @inheritParams do_findChromPeaks_centWave
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @inheritParams imputeLinInterpol
#'
#' @inheritParams findChromPeaks-matchedFilter
#'
#' @return A matrix, each row representing an identified chromatographic peak,
#' with columns:
#' \describe{
#' \item{mz}{Intensity weighted mean of m/z values of the peak across scans.}
#' \item{mzmin}{Minimum m/z of the peak.}
#' \item{mzmax}{Maximum m/z of the peak.}
#' \item{rt}{Retention time of the peak's midpoint.}
#' \item{rtmin}{Minimum retention time of the peak.}
#' \item{rtmax}{Maximum retention time of the peak.}
#' \item{into}{Integrated (original) intensity of the peak.}
#' \item{intf}{Integrated intensity of the filtered peak.}
#' \item{maxo}{Maximum intensity of the peak.}
#' \item{maxf}{Maximum intensity of the filtered peak.}
#' \item{i}{Rank of peak in merged EIC (\code{<= max}).}
#' \item{sn}{Signal to noise ratio of the peak}
#' }
#'
#' @references
#' Colin A. Smith, Elizabeth J. Want, Grace O'Maille, Ruben Abagyan and
#' Gary Siuzdak. "XCMS: Processing Mass Spectrometry Data for Metabolite
#' Profiling Using Nonlinear Peak Alignment, Matching, and Identification"
#' \emph{Anal. Chem.} 2006, 78:779-787.
#'
#' @author Colin A Smith, Johannes Rainer
#'
#' @family core peak detection functions
#'
#' @seealso \code{\link{binYonX}} for a binning function,
#' \code{\link{imputeLinInterpol}} for the interpolation of missing values.
#' \code{\link{matchedFilter}} for the standard user interface method.
#'
#' @examples
#'
#' ## Load the test file
#' data(faahko_sub)
#' ## Update the path to the files for the local system
#' dirname(faahko_sub) <- system.file("cdf/KO", package = "faahKO")
#'
#' ## Subset to one file and restrict to a certain retention time range
#' data <- filterRt(filterFile(faahko_sub, 1), c(2500, 3000))
#'
#' ## Get m/z and intensity values
#' mzs <- mz(data)
#' ints <- intensity(data)
#'
#' ## Define the values per spectrum:
#' valsPerSpect <- lengths(mzs)
#'
#' res <- do_findChromPeaks_matchedFilter(mz = unlist(mzs), int = unlist(ints),
#' scantime = rtime(data), valsPerSpect = valsPerSpect)
#' head(res)
do_findChromPeaks_matchedFilter <- function(mz,
int,
scantime,
valsPerSpect,
binSize = 0.1,
impute = "none",
baseValue,
distance,
fwhm = 30,
sigma = fwhm/2.3548,
max = 5,
snthresh = 10,
steps = 2,
mzdiff = 0.8 - binSize * steps,
index = FALSE,
sleep = 0
){
## Use original code
if (useOriginalCode()) {
return(.matchedFilter_orig(mz, int, scantime, valsPerSpect,
binSize, impute, baseValue, distance,
fwhm, sigma, max, snthresh,
steps, mzdiff, index, sleep = sleep))
} else {
return(.matchedFilter_binYonX_no_iter(mz, int, scantime, valsPerSpect,
binSize, impute, baseValue,
distance, fwhm, sigma, max,
snthresh, steps, mzdiff, index,
sleep = sleep
))
}
}
.matchedFilter_orig <- function(mz,
int,
scantime,
valsPerSpect,
binSize = 0.1,
impute = "none",
baseValue,
distance,
fwhm = 30,
sigma = fwhm/2.3548,
max = 5,
snthresh = 10,
steps = 2,
mzdiff = 0.8 - binSize * steps,
index = FALSE,
sleep = 0
){
.Deprecated(msg = paste0("Use of the original code with iterative binning",
" is discouraged!"))
## Map arguments to findPeaks.matchedFilter arguments.
step <- binSize
profMeths <- c("profBinM", "profBinLinM", "profBinLinBaseM", "profIntLinM")
names(profMeths) <- c("none", "lin", "linbase", "intlin")
impute <- match.arg(impute, names(profMeths))
profFun <- profMeths[impute]
profFun <- match.fun(profFun)
## Input argument checking.
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if (length(mz) != length(int) | length(valsPerSpect) != length(scantime)
| length(mz) != sum(valsPerSpect))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
## Calculate a the "scanindex" from the number of values per spectrum:
scanindex <- valueCount2ScanIndex(valsPerSpect)
## Create EIC buffer
mrange <- range(mz)
## Create a numeric vector of masses; these will be the mid-points of the bins.
mass <- seq(floor(mrange[1]/step)*step, ceiling(mrange[2]/step)*step, by = step)
## Calculate the /real/ bin size (as in xcms.c code).
bin_size <- (max(mass) - min(mass)) / (length(mass) - 1)
bufsize_base <- 100
bufsize <- min(bufsize_base, length(mass))
## Define profparam:
profp <- list()
if (missing(baseValue))
baseValue <- numeric()
if (length(baseValue) == 0)
baseValue <- min(int, na.rm = TRUE) / 2
profp$baselevel <- baseValue
if (missing(distance))
distance <- numeric()
if (length(distance) != 0) {
profp$basespace <- distance * bin_size
} else {
profp$basespace <- 0.075
distance <- floor(0.075 / bin_size)
}
## This returns a matrix, ncol equals the number of spectra, nrow the bufsize.
## ? named args?
buf <- profFun(x = mz, y = int, zidx = scanindex, num = bufsize,
xstart = mass[1], xend = mass[bufsize], NAOK = TRUE,
param = profp)
bufMax <- profMaxIdxM(mz, int, scanindex, bufsize, mass[1], mass[bufsize],
TRUE, profp)
bufidx <- integer(length(mass))
idxrange <- c(1, bufsize)
bufidx[idxrange[1]:idxrange[2]] <- 1:bufsize
lookahead <- steps-1
lookbehind <- 1 ## always 1?
N <- nextn(length(scantime))
xrange <- range(scantime)
x <- c(0:(N/2), -(ceiling(N/2-1)):-1)*(xrange[2]-xrange[1])/(length(scantime)-1)
filt <- -attr(eval(deriv3(~ 1/(sigma*sqrt(2*pi))*exp(-x^2/(2*sigma^2)), "x")), "hessian")
filt <- filt/sqrt(sum(filt^2))
filt <- fft(filt, inverse = TRUE)/length(filt)
cnames <- c("mz", "mzmin", "mzmax", "rt", "rtmin", "rtmax", "into", "intf",
"maxo", "maxf", "i", "sn")
rmat <- matrix(nrow = 2048, ncol = length(cnames))
num <- 0
for (i in seq(length = (length(mass)-steps+1))) {
## Update EIC buffer if necessary
if (bufidx[i+lookahead] == 0) {
bufidx[idxrange[1]:idxrange[2]] <- 0
idxrange <- c(max(1, i - lookbehind), min(bufsize+i-1-lookbehind,
length(mass)))
bufidx[idxrange[1]:idxrange[2]] <- 1:(diff(idxrange)+1)
buf <- profFun(x = mz, y = int, zidx = scanindex,
num = diff(idxrange) + 1, xstart = mass[idxrange[1]],
xend = mass[idxrange[2]], NAOK = TRUE,
param = profp)
bufMax <- profMaxIdxM(mz, int, scanindex, diff(idxrange)+1,
mass[idxrange[1]],
mass[idxrange[2]], TRUE, profp)
}
ymat <- buf[bufidx[i:(i+steps-1)],,drop=FALSE]
ysums <- colMax(ymat)
yfilt <- filtfft(ysums, filt)
gmax <- max(yfilt)
## Just look for 'max' number of peaks within the bin/slice.
for (j in seq(length = max)) {
maxy <- which.max(yfilt)
noise <- mean(ysums[ysums > 0])
##noise <- mean(yfilt[yfilt >= 0])
sn <- yfilt[maxy]/noise
if (yfilt[maxy] > 0 && yfilt[maxy] > snthresh*noise && ysums[maxy] > 0) {
peakrange <- descendZero(yfilt, maxy)
intmat <- ymat[, peakrange[1]:peakrange[2], drop = FALSE]
mzmat <- matrix(mz[bufMax[bufidx[i:(i+steps-1)],
peakrange[1]:peakrange[2]]],
nrow = steps)
which.intMax <- which.colMax(intmat)
mzmat <- mzmat[which.intMax]
if (all(is.na(mzmat))) {
yfilt[peakrange[1]:peakrange[2]] <- 0
next
}
mzrange <- range(mzmat, na.rm = TRUE)
massmean <- weighted.mean(mzmat, intmat[which.intMax], na.rm = TRUE)
## This case (the only non-na m/z had intensity 0) was reported
## by Gregory Alan Barding "binlin processing"
if(any(is.na(massmean))) {
massmean <- mean(mzmat, na.rm = TRUE)
}
pwid <- (scantime[peakrange[2]] - scantime[peakrange[1]]) /
(peakrange[2] - peakrange[1])
into <- pwid*sum(ysums[peakrange[1]:peakrange[2]])
intf <- pwid*sum(yfilt[peakrange[1]:peakrange[2]])
maxo <- max(ysums[peakrange[1]:peakrange[2]])
maxf <- yfilt[maxy]
## -- begin sleep/plot
if (sleep > 0) {
plot(scantime, yfilt, type = "l",
main = paste(mass[i], "-", mass[i+1]),
ylim = c(-gmax/3, gmax))
points(cbind(scantime, yfilt)[peakrange[1]:peakrange[2],],
type = "l", col = "red")
points(scantime, colSums(ymat), type = "l", col = "blue",
lty = "dashed")
abline(h = snthresh*noise, col = "red")
Sys.sleep(sleep)
}
## -- end sleep plot
yfilt[peakrange[1]:peakrange[2]] <- 0
num <- num + 1
## Double the size of the output matrix if it's full
if (num > nrow(rmat)) {
nrmat <- matrix(nrow = 2*nrow(rmat), ncol = ncol(rmat))
nrmat[seq(length = nrow(rmat)),] = rmat
rmat <- nrmat
}
rmat[num,] <- c(massmean, mzrange[1], mzrange[2], maxy, peakrange,
into, intf, maxo, maxf, j, sn)
} else
break
}
}
colnames(rmat) <- cnames
rmat <- rmat[seq(length = num),]
max <- max-1 + max*(steps-1) + max*ceiling(mzdiff/step)
if (index)
mzdiff <- mzdiff/step
else {
rmat[,"rt"] <- scantime[rmat[,"rt"]]
rmat[,"rtmin"] <- scantime[rmat[,"rtmin"]]
rmat[,"rtmax"] <- scantime[rmat[,"rtmax"]]
}
## Select for each unique mzmin, mzmax, rtmin, rtmax the largest peak
## and report that.
uorder <- order(rmat[,"into"], decreasing=TRUE)
uindex <- rectUnique(rmat[,c("mzmin","mzmax","rtmin","rtmax"),drop=FALSE],
uorder, mzdiff)
rmat <- rmat[uindex,,drop=FALSE]
return(rmat)
}
############################################################
## The code of this function is basically the same than of the original
## findPeaks.matchedFilter method in xcms with the following differences:
## o Create the full 'profile matrix' (i.e. the m/z binned matrix) once
## instead of repeatedly creating a "buffer" of 100 m/z values.
## o Append the identified peaks to a list instead of generating a matrix
## with a fixed set of rows which is doubled in its size each time more
## peaks are identified than there are rows in the matrix.
## o Use binYonX and imputeLinInterpol instead of the profBin... methods.
.matchedFilter_binYonX_no_iter <- function(mz,
int,
scantime,
valsPerSpect,
binSize = 0.1,
impute = "none",
baseValue,
distance,
fwhm = 30,
sigma = fwhm/2.3548,
max = 5,
snthresh = 10,
steps = 2,
mzdiff = 0.8 - binSize * steps,
index = FALSE,
sleep = 0
){
## Input argument checking.
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if (length(mz) != length(int) | length(valsPerSpect) != length(scantime)
| length(mz) != sum(valsPerSpect))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
## Generate the 'profile' matrix, i.e. perform the binning:
mrange <- range(mz[mz > 0])
mass <- seq(floor(mrange[1] / binSize) * binSize,
ceiling(mrange[2] / binSize) * binSize,
by = binSize)
## Get the imputation method: allowed: none, lin, linbase and intlin
impute <- match.arg(impute, c("none", "lin", "linbase", "intlin"))
## Select the profFun and the settings for it...
if (impute == "intlin") {
## intlin not yet implemented...
profFun = "profIntLinM"
profp <- list()
## Calculate the "scanindex" from the number of values per spectrum:
scanindex <- valueCount2ScanIndex(valsPerSpect)
bufsize <- length(mass)
buf <- do.call(profFun, args = list(mz, int, scanindex, bufsize,
mass[1], mass[bufsize],
TRUE))
## The full matrix, nrow is the total number of (binned) m/z values.
bufMax <- profMaxIdxM(mz, int, scanindex, bufsize, mass[1],
mass[bufsize], TRUE, profp)
} else {
## Binning the data.
## Create and translate settings for binYonX
toIdx <- cumsum(valsPerSpect)
fromIdx <- c(1L, toIdx[-length(toIdx)] + 1L)
shiftBy = TRUE
binFromX <- min(mass)
binToX <- max(mass)
## binSize <- (binToX - binFromX) / (length(mass) - 1)
## brks <- seq(binFromX - binSize/2, binToX + binSize/2, by = binSize)
brks <- breaks_on_nBins(fromX = binFromX, toX = binToX,
nBins = length(mass), shiftByHalfBinSize = TRUE)
binRes <- binYonX(mz, int,
breaks = brks,
fromIdx = fromIdx,
toIdx = toIdx,
baseValue = ifelse(impute == "none", yes = 0, no = NA),
sortedX = TRUE,
returnIndex = TRUE
)
if (length(toIdx) == 1)
binRes <- list(binRes)
bufMax <- do.call(cbind, lapply(binRes, function(z) return(z$index)))
bin_size <- binRes[[1]]$x[2] - binRes[[1]]$x[1]
## Missing value imputation
if (missing(baseValue))
baseValue <- numeric()
if (length(baseValue) == 0)
baseValue <- min(int, na.rm = TRUE) / 2
if (missing(distance))
distance <- numeric()
if (length(distance) == 0)
distance <- floor(0.075 / bin_size)
binVals <- lapply(binRes, function(z) {
return(imputeLinInterpol(z$y, method = impute, distance = distance,
noInterpolAtEnds = TRUE,
baseValue = baseValue))
})
buf <- do.call(cbind, binVals)
}
bufidx <- 1L:length(mass)
lookahead <- steps-1
lookbehind <- 1
N <- nextn(length(scantime))
xrange <- range(scantime)
x <- c(0:(N/2), -(ceiling(N/2-1)):-1) *
(xrange[2]-xrange[1])/(length(scantime)-1)
filt <- -attr(eval(deriv3(~ 1/(sigma*sqrt(2*pi)) *
exp(-x^2/(2*sigma^2)), "x")), "hessian")
filt <- filt/sqrt(sum(filt^2))
filt <- fft(filt, inverse = TRUE)/length(filt)
cnames <- c("mz", "mzmin", "mzmax", "rt", "rtmin", "rtmax", "into", "intf",
"maxo", "maxf", "i", "sn")
num <- 0
ResList <- list()
## Can not do much here, lapply/apply won't work because of the 'steps' parameter.
## That's looping through the masses, i.e. rows of the profile matrix.
for (i in seq(length = length(mass)-steps+1)) {
ymat <- buf[bufidx[i:(i+steps-1)], , drop = FALSE]
ysums <- colMax(ymat)
yfilt <- filtfft(ysums, filt)
gmax <- max(yfilt)
for (j in seq(length = max)) {
maxy <- which.max(yfilt)
noise <- mean(ysums[ysums > 0])
##noise <- mean(yfilt[yfilt >= 0])
sn <- yfilt[maxy]/noise
if (yfilt[maxy] > 0 && yfilt[maxy] > snthresh*noise && ysums[maxy] > 0) {
peakrange <- descendZero(yfilt, maxy)
intmat <- ymat[, peakrange[1]:peakrange[2], drop = FALSE]
mzmat <- matrix(mz[bufMax[bufidx[i:(i+steps-1)],
peakrange[1]:peakrange[2]]],
nrow = steps)
which.intMax <- which.colMax(intmat)
mzmat <- mzmat[which.intMax]
if (all(is.na(mzmat))) {
yfilt[peakrange[1]:peakrange[2]] <- 0
next
}
mzrange <- range(mzmat, na.rm = TRUE)
massmean <- weighted.mean(mzmat, intmat[which.intMax],
na.rm = TRUE)
## This case (the only non-na m/z had intensity 0) was reported
## by Gregory Alan Barding "binlin processing"
if(any(is.na(massmean))) {
massmean <- mean(mzmat, na.rm = TRUE)
}
pwid <- (scantime[peakrange[2]] - scantime[peakrange[1]]) /
(peakrange[2] - peakrange[1])
into <- pwid*sum(ysums[peakrange[1]:peakrange[2]])
intf <- pwid*sum(yfilt[peakrange[1]:peakrange[2]])
maxo <- max(ysums[peakrange[1]:peakrange[2]])
maxf <- yfilt[maxy]
## begin sleep/plot
if (sleep > 0) {
plot(scantime, yfilt, type = "l",
main = paste(mass[i], "-", mass[i+1]),
ylim=c(-gmax/3, gmax))
points(cbind(scantime, yfilt)[peakrange[1]:peakrange[2],],
type = "l", col = "red")
points(scantime, colSums(ymat), type = "l", col = "blue",
lty = "dashed")
abline(h = snthresh*noise, col = "red")
Sys.sleep(sleep)
}
## end sleep/plot
yfilt[peakrange[1]:peakrange[2]] <- 0
num <- num + 1
ResList[[num]] <- c(massmean, mzrange[1], mzrange[2], maxy,
peakrange, into, intf, maxo, maxf, j, sn)
} else
break
}
}
if (length(ResList) == 0) {
rmat <- matrix(nrow = 0, ncol = length(cnames))
colnames(rmat) <- cnames
return(rmat)
}
rmat <- do.call(rbind, ResList)
if (is.null(dim(rmat))) {
rmat <- matrix(rmat, nrow = 1)
}
colnames(rmat) <- cnames
max <- max-1 + max*(steps-1) + max*ceiling(mzdiff/binSize)
if (index)
mzdiff <- mzdiff/binSize
else {
rmat[, "rt"] <- scantime[rmat[, "rt"]]
rmat[, "rtmin"] <- scantime[rmat[, "rtmin"]]
rmat[, "rtmax"] <- scantime[rmat[, "rtmax"]]
}
## Select for each unique mzmin, mzmax, rtmin, rtmax the largest peak
## and report that.
uorder <- order(rmat[, "into"], decreasing = TRUE)
uindex <- rectUnique(rmat[, c("mzmin", "mzmax", "rtmin", "rtmax"),
drop = FALSE],
uorder, mzdiff)
rmat <- rmat[uindex,,drop = FALSE]
return(rmat)
}
############################################################
## MSW
##
#' @title Core API function for single-spectrum non-chromatography MS data
#' peak detection
#'
#' @description This function performs peak detection in mass spectrometry
#' direct injection spectrum using a wavelet based algorithm.
#'
#' @details This is a wrapper around the peak picker in Bioconductor's
#' \code{MassSpecWavelet} package calling
#' \code{\link{peakDetectionCWT}} and
#' \code{\link{tuneInPeakInfo}} functions. See the
#' \emph{xcmsDirect} vignette for more information.
#'
#' @inheritParams do_findChromPeaks_centWave
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @param ... Additional parameters to be passed to the
#' \code{\link{peakDetectionCWT}} function.
#'
#' @return A matrix, each row representing an identified peak, with columns:
#' \describe{
#' \item{mz}{m/z value of the peak at the centroid position.}
#' \item{mzmin}{Minimum m/z of the peak.}
#' \item{mzmax}{Maximum m/z of the peak.}
#' \item{rt}{Always \code{-1}.}
#' \item{rtmin}{Always \code{-1}.}
#' \item{rtmax}{Always \code{-1}.}
#' \item{into}{Integrated (original) intensity of the peak.}
#' \item{maxo}{Maximum intensity of the peak.}
#' \item{intf}{Always \code{NA}.}
#' \item{maxf}{Maximum MSW-filter response of the peak.}
#' \item{sn}{Signal to noise ratio.}
#' }
#'
#' @family core peak detection functions
#'
#' @seealso \code{\link{MSW}} for the standard user interface
#' method. \code{\link{peakDetectionCWT}} from the
#' \code{MassSpecWavelet} package.
#'
#' @author Joachim Kutzera, Steffen Neumann, Johannes Rainer
do_findPeaks_MSW <- function(mz, int, snthresh = 3,
verboseColumns = FALSE, ...) {
## Input argument checking.
if (missing(int))
stop("Argument 'int' is missing!")
if (missing(mz))
stop("Argument 'mz' is missing!")
if (length(int) != length(mz))
stop("Length of 'int' and 'mz' do not match!")
if (!is.numeric(int) | !is.numeric(mz))
stop("'int' and 'mz' are supposed to be numeric vectors!")
## MassSpecWavelet Calls
peakInfo <- peakDetectionCWT(int, SNR.Th = snthresh, ...)
majorPeakInfo <- peakInfo$majorPeakInfo
sumIntos <- function(into, inpos, scale){
scale = floor(scale)
sum(into[(inpos-scale):(inpos+scale)])
}
maxIntos <- function(into, inpos, scale){
scale = floor(scale)
max(into[(inpos-scale):(inpos+scale)])
}
betterPeakInfo <- tuneInPeakInfo(int,
majorPeakInfo)
peakIndex <- betterPeakInfo$peakIndex
nPeaks <- length(peakIndex)
## sum and max of raw values, sum and max of filter-response
rints <- numeric(nPeaks)
fints <- NA
maxRints <- numeric(nPeaks)
maxFints <- NA
for (a in 1:nPeaks) {
rints[a] <- sumIntos(int, peakIndex[a],
betterPeakInfo$peakScale[a])
maxRints[a] <- maxIntos(int, peakIndex[a],
betterPeakInfo$peakScale[a])
}
## filter-response is not summed here, the maxF-value is the one
## which was "xcmsRaw$into" earlier
## Assemble result
basenames <- c("mz","mzmin","mzmax","rt","rtmin","rtmax",
"into","maxo","sn","intf","maxf")
peaklist <- matrix(-1, nrow = nPeaks, ncol = length(basenames))
colnames(peaklist) <- c(basenames)
peaklist[,"mz"] <- mz[peakIndex]
peaklist[,"mzmin"] <- mz[(peakIndex - betterPeakInfo$peakScale)]
peaklist[,"mzmax"] <- mz[(peakIndex + betterPeakInfo$peakScale)]
## peaklist[,"rt"] <- rep(-1, length(peakIndex))
## peaklist[,"rtmin"] <- rep(-1, length(peakIndex))
## peaklist[,"rtmax"] <- rep(-1, length(peakIndex))
peaklist[,"into"] <- rints ## sum of raw-intensities
peaklist[,"maxo"] <- maxRints
peaklist[,"intf"] <- rep(NA, nPeaks)
peaklist[,"maxf"] <- betterPeakInfo$peakValue
peaklist[,"sn"] <- betterPeakInfo$peakSNR
## cat('\n')
## Filter additional (verbose) columns
if (!verboseColumns)
peaklist <- peaklist[,basenames,drop=FALSE]
peaklist
}
############################################################
## The original code
## This should be removed at some point.
.MSW_orig <- function(mz, int, snthresh = 3, verboseColumns = FALSE, ...) {
## MassSpecWavelet Calls
peakInfo <- peakDetectionCWT(int, SNR.Th=snthresh, ...)
majorPeakInfo <- peakInfo$majorPeakInfo
sumIntos <- function(into, inpos, scale){
scale=floor(scale)
sum(into[(inpos-scale):(inpos+scale)])
}
maxIntos <- function(into, inpos, scale){
scale=floor(scale)
max(into[(inpos-scale):(inpos+scale)])
}
betterPeakInfo <- tuneInPeakInfo(int,
majorPeakInfo)
peakIndex <- betterPeakInfo$peakIndex
## sum and max of raw values, sum and max of filter-response
rints<-NA;fints<-NA
maxRints<-NA;maxFints<-NA
for (a in 1:length(peakIndex)) {
rints[a] <- sumIntos(int,peakIndex[a],
betterPeakInfo$peakScale[a])
maxRints[a] <- maxIntos(int,peakIndex[a],
betterPeakInfo$peakScale[a])
}
## filter-response is not summed here, the maxF-value is the one
## which was "xcmsRaw$into" earlier
## Assemble result
basenames <- c("mz","mzmin","mzmax","rt","rtmin","rtmax",
"into","maxo","sn","intf","maxf")
peaklist <- matrix(-1, nrow = length(peakIndex), ncol = length(basenames))
colnames(peaklist) <- c(basenames)
peaklist[,"mz"] <- mz[peakIndex]
peaklist[,"mzmin"] <- mz[(peakIndex-betterPeakInfo$peakScale)]
peaklist[,"mzmax"] <- mz[(peakIndex+betterPeakInfo$peakScale)]
peaklist[,"rt"] <- rep(-1, length(peakIndex))
peaklist[,"rtmin"] <- rep(-1, length(peakIndex))
peaklist[,"rtmax"] <- rep(-1, length(peakIndex))
peaklist[,"into"] <- rints ## sum of raw-intensities
peaklist[,"maxo"] <- maxRints
peaklist[,"intf"] <- rep(NA, length(peakIndex))
peaklist[,"maxf"] <- betterPeakInfo$peakValue
peaklist[,"sn"] <- betterPeakInfo$peakSNR
cat('\n')
## Filter additional (verbose) columns
if (!verboseColumns)
peaklist <- peaklist[,basenames,drop=FALSE]
peaklist
}
############################################################
## The original code
## This should be removed at some point.
.MSW_orig <- function(mz, int, snthresh = 3, verboseColumns = FALSE, ...) {
## MassSpecWavelet Calls
peakInfo <- peakDetectionCWT(int, SNR.Th=snthresh, ...)
majorPeakInfo <- peakInfo$majorPeakInfo
sumIntos <- function(into, inpos, scale){
scale=floor(scale)
sum(into[(inpos-scale):(inpos+scale)])
}
maxIntos <- function(into, inpos, scale){
scale=floor(scale)
max(into[(inpos-scale):(inpos+scale)])
}
betterPeakInfo <- tuneInPeakInfo(int,
majorPeakInfo)
peakIndex <- betterPeakInfo$peakIndex
## sum and max of raw values, sum and max of filter-response
rints<-NA;fints<-NA
maxRints<-NA;maxFints<-NA
for (a in 1:length(peakIndex)) {
rints[a] <- sumIntos(int,peakIndex[a],
betterPeakInfo$peakScale[a])
maxRints[a] <- maxIntos(int,peakIndex[a],
betterPeakInfo$peakScale[a])
}
## filter-response is not summed here, the maxF-value is the one
## which was "xcmsRaw$into" earlier
## Assemble result
basenames <- c("mz","mzmin","mzmax","rt","rtmin","rtmax",
"into","maxo","sn","intf","maxf")
peaklist <- matrix(-1, nrow = length(peakIndex), ncol = length(basenames))
colnames(peaklist) <- c(basenames)
peaklist[,"mz"] <- mz[peakIndex]
peaklist[,"mzmin"] <- mz[(peakIndex-betterPeakInfo$peakScale)]
peaklist[,"mzmax"] <- mz[(peakIndex+betterPeakInfo$peakScale)]
peaklist[,"rt"] <- rep(-1, length(peakIndex))
peaklist[,"rtmin"] <- rep(-1, length(peakIndex))
peaklist[,"rtmax"] <- rep(-1, length(peakIndex))
peaklist[,"into"] <- rints ## sum of raw-intensities
peaklist[,"maxo"] <- maxRints
peaklist[,"intf"] <- rep(NA, length(peakIndex))
peaklist[,"maxf"] <- betterPeakInfo$peakValue
peaklist[,"sn"] <- betterPeakInfo$peakSNR
cat('\n')
## Filter additional (verbose) columns
if (!verboseColumns)
peaklist <- peaklist[,basenames,drop=FALSE]
peaklist
}
############################################################
## MS1
## This one might be too cumbersome to do it for plain vectors. It would be ideal
## for MSnExp objects though.
##
## do_findChromPeaks_MS1 <- function(mz, int, scantime, valsPerSpect) {
## ## Checks: do I have
## }
## ## Original code: TODO REMOVE ME once method is validated.
## do_predictIsotopeROIs <- function(object,
## xcmsPeaks, ppm=25,
## maxcharge=3, maxiso=5, mzIntervalExtension=TRUE) {
## if(nrow(xcmsPeaks) == 0){
## warning("Warning: There are no peaks (parameter >xcmsPeaks<) for the prediction of isotope ROIs !\n")
## return(list())
## }
## if(class(xcmsPeaks) != "xcmsPeaks")
## stop("Error: parameter >xcmsPeaks< is not of class 'xcmsPeaks' ! \n")
## if(any(is.na(match(x = c("scmin", "scmax"), table = colnames(xcmsPeaks)))))
## stop("Error: peak list >xcmsPeaks< is missing the columns 'scmin' and 'scmax' ! Please set parameter >verbose.columns< to TRUE for peak picking with 'centWave' and try again ! \n")
## addNewIsotopeROIs <- TRUE
## addNewAdductROIs <- FALSE
## polarity <- NA
## ## convert present peaks to list of lists
## presentROIs.list <- list()
## for(peakIdx in 1:nrow(xcmsPeaks)){
## presentROIs.list[[peakIdx]] <- list(
## mz = xcmsPeaks[[peakIdx, "mz"]],## XXX not used!
## mzmin = xcmsPeaks[[peakIdx, "mzmin"]],
## mzmax = xcmsPeaks[[peakIdx, "mzmax"]],
## scmin = xcmsPeaks[[peakIdx, "scmin"]],
## scmax = xcmsPeaks[[peakIdx, "scmax"]],
## length = -1,## XXX not used!
## intensity = xcmsPeaks[[peakIdx, "intb"]],## XXX not used!
## scale = xcmsPeaks[[peakIdx, "scale"]]## XXX not used!
## )
## if(abs(xcmsPeaks[[peakIdx, "mzmax"]] - xcmsPeaks[[peakIdx, "mzmin"]]) < xcmsPeaks[[peakIdx, "mz"]] * ppm / 1E6){
## presentROIs.list[[peakIdx]]$mzmin <- xcmsPeaks[[peakIdx, "mz"]] - xcmsPeaks[[peakIdx, "mz"]] * (ppm/2) / 1E6
## presentROIs.list[[peakIdx]]$mzmax <- xcmsPeaks[[peakIdx, "mz"]] + xcmsPeaks[[peakIdx, "mz"]] * (ppm/2) / 1E6
## }
## }
## ## fetch predicted ROIs
## resultObj <- createAdditionalROIs(object, presentROIs.list, ppm, addNewIsotopeROIs, maxcharge, maxiso, mzIntervalExtension, addNewAdductROIs, polarity)
## newRoiCounter <- resultObj$newRoiCounter
## numberOfAdditionalIsotopeROIs <- resultObj$numberOfAdditionalIsotopeROIs
## numberOfAdditionalAdductROIs <- resultObj$numberOfAdditionalAdductROIs
## newROI.matrix <- resultObj$newROI.matrix
## if(nrow(newROI.matrix) == 0)
## return(list())
## ## This should not be needed, as it has already been performed above.
## ## remove ROIs with weak signal content
## intensityThreshold <- 10
## newROI.matrix <- removeROIsWithoutSignal(object, newROI.matrix, intensityThreshold)
## ## convert to list of lists
## newROI.list <- list()
## for(idx in 1:nrow(newROI.matrix))
## ## c("mz", "mzmin", "mzmax", "scmin", "scmax", "length", "intensity")
## newROI.list[[length(newROI.list) + 1]] <- as.list(newROI.matrix[idx, ])
## cat("Predicted ROIs: ", length(newROI.list), " new ROIs (", numberOfAdditionalIsotopeROIs, " isotope ROIs, ", numberOfAdditionalAdductROIs, " adduct ROIs) for ", length(presentROIs.list)," present ROIs.", "\n")
## return(newROI.list)
## }
## Tuned from the original code.
#' @param peaks. \code{matrix} or \code{data.frame} with peaks for which
#' isotopes should be predicted. Required columns are \code{"mz"},
#' \code{"mzmin"}, \code{"mzmax"}, \code{"scmin"}, \code{"scmax"},
#' \code{"intb"} and \code{"scale"}.
#'
#' @return a \code{matrix} with columns \code{"mz"}, \code{"mzmin"},
#' \code{"mzmax"}, \code{"scmin"}, \code{"scmax"}, \code{"length"} (always -1),
#' \code{"intensity"} (always -1) and \code{"scale"}.
#' @noRd
do_define_isotopes <- function(peaks., maxCharge = 3, maxIso = 5,
mzIntervalExtension = TRUE) {
req_cols <- c("mz", "mzmin", "mzmax", "scmin", "scmax", "scale")
if (is.null(dim(peaks.)))
stop("'peaks.' has to be a matrix or data.frame!")
if (!all(req_cols %in% colnames(peaks.))) {
not_there <- req_cols[!(req_cols %in% colnames(peaks.))]
stop("'peaks.' lacks required columns ",
paste0("'", not_there, "'", collapse = ","), "!")
}
if (is.data.frame(peaks.))
peaks. <- as.matrix(peaks.)
isotopeDistance <- 1.0033548378
charges <- 1:maxCharge
isos <- 1:maxIso
isotopePopulationMz <- unique(as.numeric(matrix(isos, ncol = 1) %*%
(isotopeDistance / charges)))
## split the peaks into a list.
roiL <- split(peaks.[, req_cols, drop = FALSE], f = 1:nrow(peaks.))
newRois <- lapply(roiL, function(z) {
if (mzIntervalExtension)
mz_ext <- (z[3] - z[2]) * 2
else
mz_ext <- 0
return(cbind(mz = z[1] + isotopePopulationMz,
mzmin = z[2] + isotopePopulationMz - mz_ext,
mzmax = z[3] + isotopePopulationMz + mz_ext,
scmin = z[4],
scmax = z[5],
length = -1,
intensity = -1,
scale = z[6])
)
})
return(do.call(rbind, newRois))
}
#' @param peaks. see do_define_isotopes
#'
#' @param polarity character(1) defining the polarity, either \code{"positive"}
#' or \code{"negative"}.
#'
#' @note
#'
#' Reference for considered adduct distances:
#' Huang N.; Siegel M.M.1; Kruppa G.H.; Laukien F.H.; J Am Soc Mass Spectrom
#' 1999, 10, 1166-1173.
#'
#' Reference for contaminants:
#' Interferences and comtaminants encountered in modern mass spectrometry
#' Bernd O. Keller, Jie Sui, Alex B. Young and Randy M. Whittal, ANALYTICA
#' CHIMICA ACTA, 627 (1): 71-81)
#'
#' @return see do_define_isotopes.
#'
#' @noRd
do_define_adducts <- function(peaks., polarity = "positive") {
req_cols <- c("mz", "mzmin", "mzmax", "scmin", "scmax", "scale")
if (is.null(dim(peaks.)))
stop("'peaks.' has to be a matrix or data.frame!")
if (!all(req_cols %in% colnames(peaks.))) {
not_there <- req_cols[!(req_cols %in% colnames(peaks.))]
stop("'peaks.' lacks required columns ",
paste0("'", not_there, "'", collapse = ","), "!")
}
if (is.data.frame(peaks.))
peaks. <- as.matrix(peaks.)
mH <- 1.0078250322
mNa <- 22.98976928
mK <- 38.96370649
mC <- 12
mN <- 14.003074004
mO <- 15.994914620
mS <- 31.972071174
mCl <- 34.9688527
mBr <- 78.918338
mF <- 18.998403163
mDMSO <- mC * 2 + mH * 6 + mS + mO # dimethylsulfoxid
mACN <- mC * 2 + mH * 3 + mN # acetonitril
mIsoProp <- mC * 3 + mH * 8 + mO # isopropanol
mNH4 <- mN + mH * 4 # ammonium
mCH3OH <- mC + mH * 3 + mO + mH # methanol
mH2O <- mH * 2 + mO # water
mFA <- mC + mH * 2 + mO * 2 # formic acid
mHAc <- mC + mH * 3 + mC + mO + mO + mH # acetic acid
mTFA <- mC + mF * 3 + mC + mO + mO + mH # trifluoroacetic acid
switch(polarity,
"positive"={
adductPopulationMz <- unlist(c(
## [M+H]+ to [M+H]+ (Reference)
## [M+H]+ to [M+NH4]+
function(mass){ mass - mH + mNH4 },
## [M+H]+ to [M+Na]+
function(mass){ mass - mH + mNa },
## [M+H]+ to [M+CH3OH+H]+
function(mass){ mass + mCH3OH },
## [M+H]+ to [M+K]+
function(mass){ mass - mH + mK },
## [M+H]+ to [M+ACN+H]+
function(mass){ mass + mACN },
## [M+H]+ to [M+2Na-H]+
function(mass){ mass - 2 * mH + 2 * mNa },
## [M+H]+ to [M+IsoProp+H]+
function(mass){ mass + mIsoProp },
## [M+H]+ to [M+ACN+Na]+
function(mass){ mass - mH + mACN + mNa },
## [M+H]+ to [M+2K-H]+
function(mass){ mass - 2 * mH + 2 * mK },
## [M+H]+ to [M+DMSO+H]+
function(mass){ mass + mDMSO },
## [M+H]+ to [M+2*ACN+H]+
function(mass){ mass + 2 * mACN },
## [M+H]+ to [M+IsoProp+Na+H]+ TODO double-charged?
function(mass){ mass + mIsoProp + mNa },
## [M+H]+ to [2M+H]+
function(mass){ (mass - mH) * 2 + mH },
## [M+H]+ to [2M+NH4]+
function(mass){ (mass - mH) * 2 + mNH4 },
## [M+H]+ to [2M+Na]+
function(mass){ (mass - mH) * 2 + mNa },
## [M+H]+ to [2M+K]+
function(mass){ (mass - mH) * 2 + mK },
## [M+H]+ to [2M+ACN+H]+
function(mass){ (mass - mH) * 2 + mACN + mH },
## [M+H]+ to [2M+ACN+Na]+
function(mass){ (mass - mH) * 2 + mACN + mNa },
## [M+H]+ to [2M+3*H2O+2*H]2+
function(mass){((mass - mH) * 2 + 3 * mH2O + 2 * mH) / 2 },
## [M+H]+ to [M+2*H]2+
function(mass){ (mass + mH) / 2 },
## [M+H]+ to [M+H+NH4]2+
function(mass){ (mass + mNH4) / 2 },
## [M+H]+ to [M+H+Na]2+
function(mass){ (mass + mNa) / 2 },
## [M+H]+ to [M+H+K]2+
function(mass){ (mass + mK) / 2 },
## [M+H]+ to [M+ACN+2*H]2+
function(mass){ (mass + mACN + mH) / 2 },
## [M+H]+ to [M+2*Na]2+
function(mass){ (mass - mH + 2 * mNa) / 2 },
## [M+H]+ to [M+2*ACN+2*H]2+
function(mass){ (mass + 2 * mACN + mH) / 2 },
## [M+H]+ to [M+3*ACN+2*H]2+
function(mass){ (mass + 3 * mACN + mH) / 2 },
## [M+H]+ to [M+3*H]3+
function(mass){ (mass + 2 * mH) / 3 },
## [M+H]+ to [M+2*H+Na]3+
function(mass){ (mass + mH + mNa) / 3 },
## [M+H]+ to [M+H+2*Na]3+
function(mass){ (mass + 2 * mNa) / 3 },
## [M+H]+ to [M+3*Na]3+
function(mass){ (mass - mH + 3 * mNa) / 3 }
))
},
"negative" = {
adductPopulationMz <- unlist(c(
## [M-H]+ to [M-H]+ (Reference)
## [M-H]+ to [M-H2O-H]+
function(mass){ mass - mH2O },
## [M-H]+ to [M+Na-2*H]+
function(mass){ mass - mH + mNa },
## [M-H]+ to [M+Cl]+
function(mass){ mass + mH + mCl },
## [M-H]+ to [M+K-2*H]+
function(mass){ mass - mH + mK },
## [M-H]+ to [M+FA-H]+
function(mass){ mass + mFA },
## [M-H]+ to [M+HAc-H]+
function(mass){ mass + mHAc },
## [M-H]+ to [M+Br]+
function(mass){ mass + mH + mBr },
## [M-H]+ to [M+TFA-H]+
function(mass){ mass + mTFA },
## [M-H]+ to [2M-H]+
function(mass){ (mass + mH) * 2 - mH },
## [M-H]+ to [2M+FA-H]+
function(mass){ (mass + mH) * 2 + mFA - mH },
## [M-H]+ to [2M+HAc-H]+
function(mass){ (mass + mH) * 2 + mHAc - mH },
## [M-H]+ to [3M-H]+
function(mass){ (mass + mH) * 3 - mH },
## [M-H]+ to [M-2*H]2+
function(mass){ (mass - mH) / 2 },
## [M-H]+ to [M-3*H]3+
function(mass){ (mass - 2 * mH) / 3 }
))
},
"unknown"={
warning("Unknown polarity! No adduct ROIs have been added.")
},
stop("Unknown polarity (", polarity, ")!")
)
req_cols <- c("mz", "mzmin", "mzmax", "scmin", "scmax", "scale")
roiL <- split(peaks.[, req_cols, drop = FALSE], f = 1:nrow(peaks.))
newRois <- lapply(roiL, function(z) {
mzDiff <- unlist(lapply(adductPopulationMz, function(x) {
do.call(x, list(mass = z[1]))
}))
return(cbind(mz = z[1] + mzDiff,
mzmin = z[2] + mzDiff,
mzmax = z[3] + mzDiff,
scmin = z[4],
scmax = z[5],
length = -1,
intensity = -1,
scale = z[6]))
})
newRois <- do.call(rbind, newRois)
## Remove ROIs with negative or zero mzmin.
return(newRois[newRois[, "mzmin"] > 0, , drop = FALSE])
}
############################################################
## do_findKalmanROI
do_findKalmanROI <- function(mz, int, scantime, valsPerSpect,
mzrange = c(0.0, 0.0),
scanrange = c(1, length(scantime)),
minIntensity, minCentroids, consecMissedLim,
criticalVal, ppm, segs, scanBack) {
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if (length(mz) != length(int) | length(valsPerSpect) != length(scantime)
| length(mz) != sum(valsPerSpect))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
scanindex <- valueCount2ScanIndex(valsPerSpect) ## Get index vector for C calls
## Call the C function.
if (!is.double(mz))
mz <- as.double(mz)
if (!is.double(int))
int <- as.double(int)
if (!is.integer(scanindex))
scanindex <- as.integer(scanindex)
if (!is.double(scantime))
scantime <- as.double(scantime)
tmp <- capture.output(
res <- .Call("massifquant", mz, int, scanindex, scantime,
as.double(mzrange), as.integer(scanrange),
as.integer(length(scantime)), as.double(minIntensity),
as.integer(minCentroids), as.double(consecMissedLim),
as.double(ppm), as.double(criticalVal), as.integer(segs),
as.integer(scanBack), PACKAGE ='xcms' )
)
res
}
############################################################
## do_findChromPeaks_centWaveWithPredIsoROIs
## 1) Run a centWave.
## 2) Predict isotope ROIs for the identified peaks.
## 3) centWave on the predicted isotope ROIs.
## 4) combine both lists of identified peaks removing overlapping ones by
## keeping the peak with the largest signal intensity.
#' @title Core API function for two-step centWave peak detection with isotopes
#'
#' @description The \code{do_findChromPeaks_centWaveWithPredIsoROIs} performs a
#' two-step centWave based peak detection: chromatographic peaks are
#' identified using centWave followed by a prediction of the location of
#' the identified peaks' isotopes in the mz-retention time space. These
#' locations are fed as \emph{regions of interest} (ROIs) to a subsequent
#' centWave run. All non overlapping peaks from these two peak detection
#' runs are reported as the final list of identified peaks.
#'
#' @details For more details on the centWave algorithm see
#' \code{\link{centWave}}.
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @inheritParams findChromPeaks-centWaveWithPredIsoROIs
#'
#' @inheritParams do_findChromPeaks_centWave
#'
#' @family core peak detection functions
#'
#' @return A matrix, each row representing an identified chromatographic peak.
#' All non-overlapping peaks identified in both centWave runs are reported.
#' The matrix columns are:
#' \describe{
#' \item{mz}{Intensity weighted mean of m/z values of the peaks across scans.}
#' \item{mzmin}{Minimum m/z of the peaks.}
#' \item{mzmax}{Maximum m/z of the peaks.}
#' \item{rt}{Retention time of the peak's midpoint.}
#' \item{rtmin}{Minimum retention time of the peak.}
#' \item{rtmax}{Maximum retention time of the peak.}
#' \item{into}{Integrated (original) intensity of the peak.}
#' \item{intb}{Per-peak baseline corrected integrated peak intensity.}
#' \item{maxo}{Maximum intensity of the peak.}
#' \item{sn}{Signal to noise ratio, defined as \code{(maxo - baseline)/sd},
#' \code{sd} being the standard deviation of local chromatographic noise.}
#' \item{egauss}{RMSE of Gaussian fit.}
#' }
#' Additional columns for \code{verboseColumns = TRUE}:
#' \describe{
#' \item{mu}{Gaussian parameter mu.}
#' \item{sigma}{Gaussian parameter sigma.}
#' \item{h}{Gaussian parameter h.}
#' \item{f}{Region number of the m/z ROI where the peak was localized.}
#' \item{dppm}{m/z deviation of mass trace across scans in ppm.}
#' \item{scale}{Scale on which the peak was localized.}
#' \item{scpos}{Peak position found by wavelet analysis (scan number).}
#' \item{scmin}{Left peak limit found by wavelet analysis (scan number).}
#' \item{scmax}{Right peak limit found by wavelet analysis (scan numer).}
#' }
#'
#' @rdname do_findChromPeaks_centWaveWithPredIsoROIs
#'
#' @author Hendrik Treutler, Johannes Rainer
do_findChromPeaks_centWaveWithPredIsoROIs <-
function(mz, int, scantime, valsPerSpect, ppm = 25, peakwidth = c(20, 50),
snthresh = 10, prefilter = c(3, 100), mzCenterFun = "wMean",
integrate = 1, mzdiff = -0.001, fitgauss = FALSE, noise = 0,
verboseColumns = FALSE, roiList = list(),
firstBaselineCheck = TRUE, roiScales = NULL, snthreshIsoROIs = 6.25,
maxCharge = 3, maxIso = 5, mzIntervalExtension = TRUE,
polarity = "unknown", extendLengthMSW = FALSE) {
## Input argument checking: most of it will be done in
## do_findChromPeaks_centWave
polarity <- match.arg(polarity, c("positive", "negative", "unknown"))
## 1) First centWave
feats_1 <- do_findChromPeaks_centWave(mz = mz, int = int,
scantime = scantime,
valsPerSpect = valsPerSpect,
ppm = ppm,
peakwidth = peakwidth,
snthresh = snthresh,
prefilter = prefilter,
mzCenterFun = mzCenterFun,
integrate = integrate,
mzdiff = mzdiff, fitgauss = fitgauss,
noise = noise,
verboseColumns = TRUE,
roiList = roiList,
firstBaselineCheck = firstBaselineCheck,
roiScales = roiScales,
extendLengthMSW = extendLengthMSW)
return(do_findChromPeaks_addPredIsoROIs(mz = mz, int = int,
scantime = scantime,
valsPerSpect = valsPerSpect,
ppm = ppm,
peakwidth = peakwidth,
snthresh = snthreshIsoROIs,
prefilter = prefilter,
mzCenterFun = mzCenterFun,
integrate = integrate,
mzdiff = mzdiff,
fitgauss = fitgauss,
noise = noise,
verboseColumns = verboseColumns,
peaks. = feats_1,
maxCharge = maxCharge,
maxIso = maxIso,
mzIntervalExtension = mzIntervalExtension,
polarity = polarity))
}
#' @description The \code{do_findChromPeaks_centWaveAddPredIsoROIs} performs
#' centWave based peak detection based in regions of interest (ROIs)
#' representing predicted isotopes for the peaks submitted with argument
#' \code{peaks.}. The function returns a matrix with the identified peaks
#' consisting of all input peaks and peaks representing predicted isotopes
#' of these (if found by the centWave algorithm).
#'
#' @param peaks. A matrix or \code{xcmsPeaks} object such as one returned by
#' a call to \code{link{do_findChromPeaks_centWave}} or
#' \code{link{findPeaks.centWave}} (both with \code{verboseColumns = TRUE})
#' with the peaks for which isotopes should be predicted and used for an
#' additional peak detectoin using the centWave method. Required columns
#' are: \code{"mz"}, \code{"mzmin"}, \code{"mzmax"}, \code{"scmin"},
#' \code{"scmax"}, \code{"scale"} and \code{"into"}.
#'
#' @param snthresh For \code{do_findChromPeaks_addPredIsoROIs}:
#' numeric(1) defining the signal to noise threshold for the centWave
#' algorithm. For \code{do_findChromPeaks_centWaveWithPredIsoROIs}:
#' numeric(1) defining the signal to noise threshold for the initial
#' (first) centWave run.
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @inheritParams do_findChromPeaks_centWave
#'
#' @rdname do_findChromPeaks_centWaveWithPredIsoROIs
do_findChromPeaks_addPredIsoROIs <-
function(mz, int, scantime, valsPerSpect, ppm = 25, peakwidth = c(20, 50),
snthresh = 6.25, prefilter = c(3, 100), mzCenterFun = "wMean",
integrate = 1, mzdiff = -0.001, fitgauss = FALSE, noise = 0,
verboseColumns = FALSE, peaks. = NULL,
maxCharge = 3, maxIso = 5, mzIntervalExtension = TRUE,
polarity = "unknown") {
polarity <- match.arg(polarity, c("positive", "negative", "unknown"))
## These variables might at some point be added as function args.
addNewIsotopeROIs <- TRUE
addNewAdductROIs <- FALSE
## 2) predict isotope and/or adduct ROIs
f_mod <- peaks.
## Extend the mzmin and mzmax if needed.
tittle <- peaks.[, "mz"] * (ppm / 2) / 1E6
expand_mz <- (peaks.[, "mzmax"] - peaks.[, "mzmin"]) < (tittle * 2)
if (any(expand_mz)) {
f_mod[expand_mz, "mzmin"] <- peaks.[expand_mz, "mz"] -
tittle[expand_mz]
f_mod[expand_mz, "mzmax"] <- peaks.[expand_mz, "mz"] + tittle[expand_mz]
}
## Add predicted ROIs
if (addNewIsotopeROIs) {
iso_ROIs <- do_define_isotopes(peaks. = f_mod,
maxCharge = maxCharge,
maxIso = maxIso,
mzIntervalExtension = mzIntervalExtension)
} else {
iso_ROIs <- matrix(nrow = 0, ncol = 8)
colnames(iso_ROIs) <- c("mz", "mzmin", "mzmax", "scmin", "scmax",
"length", "intensity", "scale")
}
if (addNewAdductROIs) {
add_ROIs <- do_define_adducts(peaks. = f_mod, polarity = polarity)
} else {
add_ROIs <- matrix(nrow = 0, ncol = 8)
colnames(iso_ROIs) <- c("mz", "mzmin", "mzmax", "scmin", "scmax",
"length", "intensity", "scale")
}
newROIs <- rbind(iso_ROIs, add_ROIs)
rm(f_mod)
if (nrow(newROIs) == 0)
return(peaks.)
## Remove ROIs that are out of mz range:
mz_range <- range(mz)
newROIs <- newROIs[newROIs[, "mzmin"] >= mz_range[1] &
newROIs[, "mzmax"] <= mz_range[2], , drop = FALSE]
## Remove ROIs with too low signal:
keep_me <- logical(nrow(newROIs))
scanindex <- as.integer(valueCount2ScanIndex(valsPerSpect))
for (i in 1:nrow(newROIs)) {
vals <- .Call("getEIC", mz, int, scanindex,
as.double(newROIs[i, c("mzmin", "mzmax")]),
as.integer(newROIs[i, c("scmin", "scmax")]),
as.integer(length(scantime)), PACKAGE ='xcms' )
keep_me[i] <- sum(vals$intensity, na.rm = TRUE) >= 10
}
newROIs <- newROIs[keep_me, , drop = FALSE]
if (nrow(newROIs) == 0) {
warning("No isotope or adduct ROIs for the identified peaks with a ",
"valid signal found!")
return(peaks.)
}
## 3) centWave using the identified ROIs.
roiL <- split(as.data.frame(newROIs), f = 1:nrow(newROIs))
feats_2 <- do_findChromPeaks_centWave(mz = mz, int = int,
scantime = scantime,
valsPerSpect = valsPerSpect,
ppm = ppm, peakwidth = peakwidth,
snthresh = snthresh,
prefilter = prefilter,
mzCenterFun = mzCenterFun,
integrate = integrate,
mzdiff = mzdiff, fitgauss = fitgauss,
noise = noise,
verboseColumns = verboseColumns,
roiList = roiL,
firstBaselineCheck = FALSE,
roiScales = newROIs[, "scale"])
## Clean up of the results:
if (nrow(feats_2) > 0) {
## remove NaNs
any_na <- is.na(rowSums(feats_2[, c("mz", "mzmin", "mzmax", "rt",
"rtmin", "rtmax")]))
if (any(any_na))
feats_2 <- feats_2[!any_na, , drop = FALSE]
no_mz_width <- (feats_2[, "mzmax"] - feats_2[, "mzmin"]) == 0
no_rt_width <- (feats_2[, "rtmax"] - feats_2[, "rtmin"]) == 0
no_area <- no_mz_width | no_rt_width
if (any(no_area))
feats_2 <- feats_2[!no_area, , drop = FALSE]
}
## 4) Check and remove ROIs overlapping with peaks.
if (nrow(feats_2) > 0) {
## Comparing each ROI with each peak; slightly modified from the
## original code in which we prevent calling apply followed by
## two lapply.
## Update: we're no longer removing original peaks, as they are
## themselfs overlapping, thus we would remove too many.
removeROIs <- rep(FALSE, nrow(feats_2))
overlapProportionThreshold <- 0.01
for (i in 1:nrow(feats_2)) {
## Compare ROI i with all peaks (peaks) and check if its
## overlapping
## mz
roiMzCenter <- (feats_2[i, "mzmin"] + feats_2[i, "mzmax"]) / 2
peakMzCenter <- (peaks.[, "mzmin"] + peaks.[, "mzmax"]) / 2
roiMzRadius <- (feats_2[i, "mzmax"] - feats_2[i, "mzmin"]) / 2
peakMzRadius <- (peaks.[, "mzmax"] - peaks.[, "mzmin"]) / 2
overlappingMz <- abs(peakMzCenter - roiMzCenter) <=
(roiMzRadius + peakMzRadius)
## rt
roiRtCenter <- (feats_2[i, "rtmin"] + feats_2[i, "rtmax"]) / 2
peakRtCenter <- (peaks.[, "rtmin"] + peaks.[, "rtmax"]) / 2
roiRtRadius <- (feats_2[i, "rtmax"] - feats_2[i, "rtmin"]) / 2
peakRtRadius <- (peaks.[, "rtmax"] - peaks.[, "rtmin"]) / 2
overlappingRt <- abs(peakRtCenter - roiRtCenter) <=
(roiRtRadius + peakRtRadius)
is_overlapping <- overlappingMz & overlappingRt
## Now determine whether we remove the ROI or the peak,
## depending on the raw signal intensity.
if (any(is_overlapping)) {
if (any(peaks.[is_overlapping, "into"] >
feats_2[i, "into"]))
removeROIs[i] <- TRUE
}
}
feats_2 <- feats_2[!removeROIs, , drop = FALSE]
}
if (!verboseColumns)
peaks. <- peaks.[ , c("mz", "mzmin", "mzmax", "rt", "rtmin",
"rtmax", "into", "intb", "maxo", "sn")]
if (nrow(feats_2))
rbind(peaks., feats_2)
else
peaks.
}
do_findChromPeaks_addPredIsoROIs_mod <-
function(mz, int, scantime, valsPerSpect, ppm = 25, peakwidth = c(20, 50),
snthresh = 6.25, prefilter = c(3, 100), mzCenterFun = "wMean",
integrate = 1, mzdiff = -0.001, fitgauss = FALSE, noise = 0,
verboseColumns = FALSE, peaks. = NULL,
maxCharge = 3, maxIso = 5, mzIntervalExtension = TRUE,
polarity = "unknown") {
## Input argument checking: most of it will be done in
## do_findChromPeaks_centWave
polarity <- match.arg(polarity, c("positive", "negative", "unknown"))
## These variables might at some point be added as function args.
addNewIsotopeROIs <- TRUE
addNewAdductROIs <- FALSE
## 2) predict isotope and/or adduct ROIs
f_mod <- peaks.
## Extend the mzmin and mzmax if needed.
tittle <- peaks.[, "mz"] * (ppm / 2) / 1E6
expand_mz <- (peaks.[, "mzmax"] - peaks.[, "mzmin"]) < (tittle * 2)
if (any(expand_mz)) {
f_mod[expand_mz, "mzmin"] <- peaks.[expand_mz, "mz"] -
tittle[expand_mz]
f_mod[expand_mz, "mzmax"] <- peaks.[expand_mz, "mz"] + tittle[expand_mz]
}
## Add predicted ROIs
if (addNewIsotopeROIs) {
iso_ROIs <- do_define_isotopes(peaks. = f_mod,
maxCharge = maxCharge,
maxIso = maxIso,
mzIntervalExtension = mzIntervalExtension)
} else {
iso_ROIs <- matrix(nrow = 0, ncol = 8)
colnames(iso_ROIs) <- c("mz", "mzmin", "mzmax", "scmin", "scmax",
"length", "intensity", "scale")
}
if (addNewAdductROIs) {
add_ROIs <- do_define_adducts(peaks. = f_mod, polarity = polarity)
} else {
add_ROIs <- matrix(nrow = 0, ncol = 8)
colnames(iso_ROIs) <- c("mz", "mzmin", "mzmax", "scmin", "scmax",
"length", "intensity", "scale")
}
newROIs <- rbind(iso_ROIs, add_ROIs)
rm(f_mod)
if (nrow(newROIs) == 0)
return(peaks.)
## Remove ROIs that are out of mz range:
mz_range <- range(mz)
newROIs <- newROIs[newROIs[, "mzmin"] >= mz_range[1] &
newROIs[, "mzmax"] <= mz_range[2], , drop = FALSE]
## Remove ROIs with too low signal:
keep_me <- logical(nrow(newROIs))
scanindex <- as.integer(valueCount2ScanIndex(valsPerSpect))
for (i in 1:nrow(newROIs)) {
vals <- .Call("getEIC", mz, int, scanindex,
as.double(newROIs[i, c("mzmin", "mzmax")]),
as.integer(newROIs[i, c("scmin", "scmax")]),
as.integer(length(scantime)), PACKAGE ='xcms' )
keep_me[i] <- sum(vals$intensity, na.rm = TRUE) >= 10
}
newROIs <- newROIs[keep_me, , drop = FALSE]
if (nrow(newROIs) == 0) {
warning("No isotope or adduct ROIs for the identified peaks with a ",
"valid signal found!")
return(peaks.)
}
cat("No. of input peaks: ", nrow(peaks.), "\n")
## 3) centWave using the identified ROIs.
roiL <- split(as.data.frame(newROIs), f = 1:nrow(newROIs))
cat("Identified iso ROIs: ", length(roiL), "\n")
feats_2 <- do_findChromPeaks_centWave(mz = mz, int = int,
scantime = scantime,
valsPerSpect = valsPerSpect,
ppm = ppm, peakwidth = peakwidth,
snthresh = snthresh,
prefilter = prefilter,
mzCenterFun = mzCenterFun,
integrate = integrate,
mzdiff = mzdiff, fitgauss = fitgauss,
noise = noise,
verboseColumns = verboseColumns,
roiList = roiL,
firstBaselineCheck = FALSE,
roiScales = newROIs[, "scale"])
cat("No. of chrom. peaks found in ROIs: ", nrow(feats_2), "\n")
## Clean up of the results:
if (nrow(feats_2) > 0) {
## remove NaNs
any_na <- is.na(rowSums(feats_2[, c("mz", "mzmin", "mzmax", "rt",
"rtmin", "rtmax")]))
if (any(any_na))
feats_2 <- feats_2[!any_na, , drop = FALSE]
no_mz_width <- (feats_2[, "mzmax"] - feats_2[, "mzmin"]) == 0
no_rt_width <- (feats_2[, "rtmax"] - feats_2[, "rtmin"]) == 0
cat("No. of peaks with NA values: ", sum(any_na), "\n")
cat("No. of peaks without mz width: ", sum(no_mz_width), "\n")
cat("No. of peaks without rt width: ", sum(no_rt_width), "\n")
## remove empty area
## no_area <- (feats_2[, "mzmax"] - feats_2[, "mzmin"]) == 0 ||
## (feats_2[, "rtmax"] - feats_2[, "rtmin"]) == 0
## no_area <- no_mz_width || no_rt_width
no_area <- no_mz_width
if (any(no_area))
feats_2 <- feats_2[!no_area, , drop = FALSE]
}
cat("After removing NAs or empty are peaks: ", nrow(feats_2), "\n")
## 4) Check and remove ROIs overlapping with peaks.
if (nrow(feats_2) > 0) {
## Comparing each ROI with each peak; slightly modified from the original
## code in which we prevent calling apply followed by two lapply.
removeROIs <- rep(FALSE, nrow(feats_2))
removeFeats <- rep(FALSE, nrow(peaks.))
overlapProportionThreshold <- 0.01
for (i in 1:nrow(feats_2)) {
## Compare ROI i with all peaks (peaks) and check if its
## overlapping
## mz
roiMzCenter <- (feats_2[i, "mzmin"] + feats_2[i, "mzmax"]) / 2
peakMzCenter <- (peaks.[, "mzmin"] + peaks.[, "mzmax"]) / 2
roiMzRadius <- (feats_2[i, "mzmax"] - feats_2[i, "mzmin"]) / 2
peakMzRadius <- (peaks.[, "mzmax"] - peaks.[, "mzmin"]) / 2
overlappingMz <- abs(peakMzCenter - roiMzCenter) <=
(roiMzRadius + peakMzRadius)
## rt
roiRtCenter <- (feats_2[i, "rtmin"] + feats_2[i, "rtmax"]) / 2
peakRtCenter <- (peaks.[, "rtmin"] + peaks.[, "rtmax"]) / 2
roiRtRadius <- (feats_2[i, "rtmax"] - feats_2[i, "rtmin"]) / 2
peakRtRadius <- (peaks.[, "rtmax"] - peaks.[, "rtmin"]) / 2
overlappingRt <- abs(peakRtCenter - roiRtCenter) <=
(roiRtRadius + peakRtRadius)
is_overlapping <- overlappingMz & overlappingRt
## Now determine whether we remove the ROI or the peak, depending
## on the raw signal intensity.
if (any(is_overlapping)) {
if (any(peaks.[is_overlapping, "into"] > feats_2[i, "into"])) {
removeROIs[i] <- TRUE
} else {
removeFeats[is_overlapping] <- TRUE
}
}
}
feats_2 <- feats_2[!removeROIs, , drop = FALSE]
peaks. <- peaks.[!removeFeats, , drop = FALSE]
}
cat("After removing overlapping peaks: ", nrow(feats_2), "\n")
cat("After removing overlapping peaks (peaks.): ", nrow(peaks.), "\n")
if (!verboseColumns)
peaks. <- peaks.[ , c("mz", "mzmin", "mzmax", "rt", "rtmin",
"rtmax", "into", "intb", "maxo", "sn")]
## For now just return the new ones.
return(feats_2)
if (nrow(feats_2) == 0)
return(peaks.)
else
return(rbind(peaks., feats_2))
}
#' @title Identify peaks in chromatographic data using matchedFilter
#'
#' @description
#'
#' The function performs peak detection using the [matchedFilter] algorithm
#' on chromatographic data (i.e. with only intensities and retention time).
#'
#' @param int `numeric` with intensity values.
#'
#' @param rt `numeric` with the retention time for the intensities. Length has
#' to be equal to `length(int)`.
#'
#' @param fwhm `numeric(1)` specifying the full width at half maximum
#' of matched filtration gaussian model peak. Only used to calculate the
#' actual sigma, see below.
#'
#' @param sigma `numeric(1)` specifying the standard deviation (width)
#' of the matched filtration model peak.
#'
#' @param max `numeric(1)` with the maximal number of peaks that are expected/
#' will bbe detected in the data
#'
#' @param snthresh `numeric(1)` defining the signal to noise cut-off to be used
#' in the peak detection step.
#'
#' @param ... currently ignored.
#'
#' @family peak detection functions for chromatographic data
#'
#' @seealso [matchedFilter] for a detailed description of the peak detection
#' method.
#'
#' @author Johannes Rainer
#'
#' @return
#'
#' A matrix, each row representing an identified chromatographic peak, with
#' columns:
#'
#' - `"rt"`: retention time of the peak's midpoint (time of the maximum signal).
#' - `"rtmin"`: minimum retention time of the peak.
#' - `"rtmax"`: maximum retention time of the peak.
#' - `"into"`: integrated (original) intensity of the peak.
#' - `"intf"`: integrated intensity of the filtered peak.
#' - `"maxo"`: maximum (original) intensity of the peak.
#' - `"maxf"`" maximum intensity of the filtered peak.
#' - `"sn"`: signal to noise ratio of the peak.
#'
#' @md
#'
#' @examples
#'
#' ## Load the test file
#' data(faahko_sub)
#' ## Update the path to the files for the local system
#' dirname(faahko_sub) <- system.file("cdf/KO", package = "faahKO")
#'
#' ## Subset to one file and drop identified chromatographic peaks
#' data <- dropChromPeaks(filterFile(faahko_sub, 1))
#'
#' ## Extract chromatographic data for a small m/z range
#' chr <- chromatogram(data, mz = c(272.1, 272.3), rt = c(3000, 3200))[1, 1]
#'
#' pks <- peaksWithMatchedFilter(intensity(chr), rtime(chr))
#' pks
#'
#' ## Plotting the data
#' plot(rtime(chr), intensity(chr), type = "h")
#' rect(xleft = pks[, "rtmin"], xright = pks[, "rtmax"], ybottom = c(0, 0),
#' ytop = pks[, "maxo"], border = "red")
peaksWithMatchedFilter <- function(int, rt, fwhm = 30, sigma = fwhm / 2.3548,
max = 20, snthresh = 10, ...) {
if (missing(int) | missing(rt))
stop("Arguments 'int' and 'rt' are required")
if (length(int) != length(rt))
stop("'int' and 'rt' must have the same length")
## Replace NAs with 0 - that's how the original code handled it.
nas <- is.na(int)
int[nas] <- 0
n_vals <- length(int)
N <- nextn(n_vals)
rtrange <- range(rt)
x <- c(0:(N / 2), -(ceiling(N / 2 - 1)):-1) *
(rtrange[2] - rtrange[1]) / (n_vals - 1)
filt <- -attr(eval(deriv3(~ 1 / (sigma * sqrt(2 * pi)) *
exp(-x^2 / (2 * sigma^2)), "x")),
"hessian")
filt <- filt / sqrt(sum(filt^2))
filt <- fft(filt, inverse = TRUE) / length(filt)
cnames <- c("rt", "rtmin", "rtmax", "into", "intf", "maxo", "maxf", "sn")
num <- 0
ResList <- list()
int_filt <- filtfft(int, filt)
glob_max <- max(int_filt)
for (j in seq(length = max)) {
max_idx <- which.max(int_filt)
noise <- mean(int[int > 0])
##noise <- mean(yfilt[yfilt >= 0])
sn <- int_filt[max_idx] / noise
if (int_filt[max_idx] > 0 && int_filt[max_idx] > snthresh * noise &&
int[max_idx] > 0) {
peak_range <- descendZero(int_filt, max_idx)
peak_range_idx <- peak_range[1]:peak_range[2]
## Define into and intf, i.e. the integrated signal.
peak_width <- diff(rt[peak_range]) / diff(peak_range)
into <- peak_width * sum(int[peak_range_idx])
intf <- peak_width * sum(int_filt[peak_range_idx])
num <- num + 1
ResList[[num]] <- c(rt[max_idx], rt[peak_range], into, intf,
max(int[peak_range_idx]), int_filt[max_idx], sn)
## "remove" current peak from the data
int_filt[peak_range_idx] <- 0
} else
break
}
if (length(ResList)) {
res <- do.call(rbind, ResList)
colnames(res) <- cnames
} else {
warning("No peaks found with current settings")
res <- matrix(nrow = 0, ncol = length(cnames),
dimnames = list(character(), cnames))
}
res
}
#' @title Identify peaks in chromatographic data using centWave
#'
#' @description
#'
#' `peaksWithCentWave` identifies (chromatographic) peaks in purely
#' chromatographic data, i.e. based on intensity and retention time values
#' without m/z values.
#'
#' @details
#'
#' The method uses the same algorithm for the peak detection than [centWave],
#' employs however a different approach to identify the initial regions in
#' which the peak detection is performed (i.e. the *regions of interest* ROI).
#' The method first identifies all local maxima in the chromatographic data and
#' defines the corresponding positions +/- `peakwidth[2]` as the ROIs. Noise
#' estimation bases also on these ROIs and can thus be different from [centWave]
#' resulting in different signal to noise ratios.
#'
#' @param int `numeric` with intensity values.
#'
#' @param rt `numeric` with the retention time for the intensities. Length has
#' to be equal to `length(int)`.
#'
#' @param peakwidth `numeric(2)` with the lower and upper bound of the
#' expected peak width.
#'
#' @param snthresh `numeric(1)` defining the signal to noise ratio cutoff.
#' Peaks with a signal to noise ratio < `snthresh` are omitted.
#'
#' @param prefilter `numeric(2)` (`c(k, I)`): only regions of interest with at
#' least `k` centroids with signal `>= I` are returned in the first
#' step.
#'
#' @param integrate `numeric(1)`, integration method. For `integrate = 1` peak
#' limits are found through descending on the mexican hat filtered data,
#' for `integrate = 2` the descend is done on the real data. The latter
#' method is more accurate but prone to noise, while the former is more
#' robust, but less exact.
#'
#' @param fitgauss `logical(1)` whether or not a Gaussian should be fitted
#' to each peak.
#'
#' @param noise `numeric(1)` defining the minimum required intensity for
#' centroids to be considered in the first analysis step (definition of
#' the *regions of interest*).
#'
#' @param verboseColumns `logical(1)`: whether additional peak meta data
#' columns should be returned.
#'
#' @param firstBaselineCheck `logical(1)`. If `TRUE` continuous data within
#' regions of interest is checked to be above the first baseline.
#'
#' @param extendLengthMSW `logical(1)`. If `TRUE` the "open" method of EIC
#' extension is used, rather than the default "reflect" method.
#'
#' @param ... currently ignored.
#'
#' @family peak detection functions for chromatographic data
#'
#' @seealso [centWave] for a detailed description of the peak detection
#' method.
#'
#' @author Johannes Rainer
#'
#' @return
#'
#' A matrix, each row representing an identified chromatographic peak, with
#' columns:
#'
#' - `"rt"`: retention time of the peak's midpoint (time of the maximum signal).
#' - `"rtmin"`: minimum retention time of the peak.
#' - `"rtmax"`: maximum retention time of the peak.
#' - `"into"`: integrated (original) intensity of the peak.
#' - `"intb"`: per-peak baseline corrected integrated peak intensity.
#' - `"maxo"`: maximum (original) intensity of the peak.
#' - `"sn"`: signal to noise ratio of the peak defined as
#' `(maxo - baseline)/sd` with `sd` being the standard deviation of the local
#' chromatographic noise.
#'
#' Additional columns for `verboseColumns = TRUE`:
#'
#' - `"mu"`: gaussian parameter mu.
#' - `"sigma"`: gaussian parameter sigma.
#' - `"h"`: gaussian parameter h.
#' - `"f"`: region number of the m/z ROI where the peak was localized.
#' - `"dppm"`: m/z deviation of mass trace across scans in ppm (always `NA`).
#' - `"scale"`: scale on which the peak was localized.
#' - `"scpos"`: peak position found by wavelet analysis (index in `int`).
#' - `"scmin"`: left peak limit found by wavelet analysis (index in `int`).
#' - `"scmax"`: right peak limit found by wavelet analysis (index in `int`).
#'
#' @md
#'
#' @examples
#'
#' ## Reading a file
#' library(xcms)
#' od <- readMSData(system.file("cdf/KO/ko15.CDF", package = "faahKO"),
#' mode = "onDisk")
#'
#' ## Extract chromatographic data for a small m/z range
#' mzr <- c(272.1, 272.2)
#' chr <- chromatogram(od, mz = mzr, rt = c(3000, 3300))[1, 1]
#'
#' int <- intensity(chr)
#' rt <- rtime(chr)
#'
#' ## Plot the region
#' plot(chr, type = "h")
#'
#' ## Identify peaks in the chromatographic data
#' pks <- peaksWithCentWave(intensity(chr), rtime(chr))
#' pks
#'
#' ## Highlight the peaks
#' rect(xleft = pks[, "rtmin"], xright = pks[, "rtmax"],
#' ybottom = rep(0, nrow(pks)), ytop = pks[, "maxo"], col = "#ff000040",
#' border = "#00000040")
peaksWithCentWave <- function(int, rt,
peakwidth = c(20, 50),
snthresh = 10,
prefilter = c(3, 100),
integrate = 1,
fitgauss = FALSE,
noise = 0, ## noise.local=TRUE,
verboseColumns = FALSE,
firstBaselineCheck = TRUE,
extendLengthMSW = FALSE,
...
) {
if (length(peakwidth) != 2)
stop("'peakwidth' has to be a numeric of length 2")
## Avoid NAs
int[is.na(int)] <- 0
rois <- .getRtROI(int, rt, peakwidth = peakwidth, noise = noise,
prefilter = prefilter)
basenames <- c("mz", "mzmin", "mzmax", "rt", "rtmin", "rtmax", "into",
"intb", "maxo", "sn")
verbosenames <- c("egauss", "mu", "sigma", "h", "f", "dppm", "scale",
"scpos", "scmin", "scmax", "lmin", "lmax")
peaks_names <- c(basenames, verbosenames)
peaks_ncols <- length(peaks_names)
peakinfo_names <- c("scale", "scaleNr", "scpos", "scmin", "scmax")
## Peak width: seconds to scales
scalerange <- round((peakwidth / mean(diff(rt))) / 2)
if (length(z <- which(scalerange == 0)))
scalerange <- scalerange[-z]
if (length(scalerange) < 1) {
warning("No scales? Please check peak width!")
if (verboseColumns)
basenames <- c(basenames, verbosenames)
return(invisible(
matrix(nrow = 0, ncol = length(basenames),
dimnames = list(character(), basenames))[, -(1:3), drop = FALSE]))
}
if (length(scalerange) > 1)
scales <- seq(from = scalerange[1], to = scalerange[2], by = 2)
else
scales <- scalerange
minPeakWidth <- scales[1]
noiserange <- c(ceiling(minPeakWidth) * 3, max(scales) * 3)
maxGaussOverlap <- 0.5
minPtsAboveBaseLine <- max(4, minPeakWidth - 2)
minCentroids <- minPtsAboveBaseLine
scRangeTol <- maxDescOutlier <- floor(minPeakWidth / 2)
scanrange <- c(1, length(rt))
Nscantime <- length(int)
## mzdiff <- -0.001
mzdiff <- 0
peaklist <- NULL
for (i in seq_len(nrow(rois))) {
scmin <- rois[i, "scmin"]
scmax <- rois[i, "scmax"]
N <- scmax - scmin + 1
peaks <- matrix(ncol = peaks_ncols, nrow = 0,
dimnames = list(character(), peaks_names))
peakinfo <- matrix(ncol = 5, nrow = 0,
dimnames = list(character(), peakinfo_names))
## Could also return the "correct one..."
sccenter <- scmin + floor(N/2) - 1
## sccenter <- rois[i, "sccent"]
scrange <- c(scmin, scmax)
## scrange + noiserange, used for baseline detection and wavelet analysis
sr <- c(max(scanrange[1], scrange[1] - max(noiserange)),
min(scanrange[2], scrange[2] + max(noiserange)))
## Intensities for baseline detection and wavelet analysis
td <- sr[1]:sr[2]
d <- int[td]
scan.range <- c(sr[1], sr[2])
## the ROI
otd <- scmin:scmax
od <- int[otd]
if (all(od == 0)) {
warning("centWave: no peaks found in ROI.")
next
}
## scrange + scRangeTol, used for gauss fitting and continuous
## data above 1st baseline detection
ftd <- max(td[1], scrange[1] - scRangeTol):min(td[length(td)],
scrange[2] + scRangeTol)
fd <- int[ftd]
## 1st type of baseline: statistic approach
## in case of very long mass trace use full scan range
## for baseline detection
if (N >= 10 * minPeakWidth) {
noised <- int
} else {
noised <- d
}
## 90% trimmed mean as first baseline guess
noise <- xcms:::estimateChromNoise(noised, trim = 0.05,
minPts = 3 * minPeakWidth)
## any continuous data above 1st baseline ?
if (firstBaselineCheck &
!continuousPtsAboveThreshold(fd, threshold = noise,
num = minPtsAboveBaseLine))
next
## 2nd baseline estimate using not-peak-range
lnoise <- xcms:::getLocalNoiseEstimate(d, td, ftd, noiserange, Nscantime,
threshold = noise,
num = minPtsAboveBaseLine)
## Final baseline & Noise estimate
baseline <- max(1, min(lnoise[1], noise))
sdnoise <- max(1, lnoise[2])
sdthr <- sdnoise * snthresh
## is there any data above S/N * threshold ?
if (!(any(fd - baseline >= sdthr)))
next
wCoefs <- xcms:::MSW.cwt(d, scales = scales, wavelet = 'mexh',
extendLengthMSW = extendLengthMSW)
if (!(!is.null(dim(wCoefs)) && any((wCoefs - baseline) >= sdthr)))
next
if (td[length(td)] == Nscantime) ## workaround, localMax fails otherwise
wCoefs[nrow(wCoefs),] <- wCoefs[nrow(wCoefs) - 1, ] * 0.99
localMax <- xcms:::MSW.getLocalMaximumCWT(wCoefs)
rL <- xcms:::MSW.getRidge(localMax)
wpeaks <- sapply(rL,
function(x) {
w <- min(1:length(x), ncol(wCoefs))
any((wCoefs[x,w] - baseline) >= sdthr)
})
if (any(wpeaks)) {
wpeaksidx <- which(wpeaks)
## check each peak in ridgeList
for (p in 1:length(wpeaksidx)) {
opp <- rL[[wpeaksidx[p]]]
pp <- unique(opp) ## NOTE: this is not ordered!
if (length(pp) >= 1) {
dv <- td[pp] %in% ftd
if (any(dv)) { ## peaks in orig. data range
## Final S/N check
if (any(d[pp[dv]] - baseline >= sdthr)) {
## ## allow roiScales to be a numeric of length 0
## if(length(roiScales) > 0) {
## ## use given scale
## best.scale.nr <- which(scales == roiScales[[f]])
## if(best.scale.nr > length(opp))
## best.scale.nr <- length(opp)
## } else {
## try to decide which scale describes the peak best
inti <- numeric(length(opp))
irange <- rep(ceiling(scales[1]/2), length(opp))
for (k in 1:length(opp)) {
kpos <- opp[k]
r1 <- ifelse(kpos - irange[k] > 1,
kpos - irange[k], 1)
r2 <- ifelse(kpos + irange[k] < length(d),
kpos + irange[k], length(d))
inti[k] <- sum(d[r1:r2])
}
maxpi <- which.max(inti)
if (length(maxpi) > 1) {
m <- wCoefs[opp[maxpi], maxpi]
bestcol <- which(m == max(m),
arr.ind = TRUE)[2]
best.scale.nr <- maxpi[bestcol]
} else {
best.scale.nr <- maxpi
}
best.scale <- scales[best.scale.nr]
best.scale.pos <- opp[best.scale.nr]
pprange <- min(pp):max(pp)
lwpos <- max(1, best.scale.pos - best.scale)
rwpos <- min(best.scale.pos + best.scale, length(td))
p1 <- match(td[lwpos], otd)[1]
p2 <- match(td[rwpos], otd)
p2 <- p2[length(p2)]
if (is.na(p1)) p1 <- 1
if (is.na(p2)) p2 <- N
maxint <- max(od[p1:p2])
peaks <- rbind(
peaks,
c(1, 1, 1, # mz, mzmin, mzmax,
NA, NA, NA, # rt, rtmin, rtmax,
NA, # intensity (sum)
NA, # intensity (-bl)
maxint, # max intensity
round((maxint - baseline) / sdnoise), # S/N Ratio
NA, # Gaussian RMSE
NA,NA,NA, # Gaussian Parameters
i, # ROI Position
NA, # max. difference between the [minCentroids] peaks in ppm
best.scale, # Scale
td[best.scale.pos],
td[lwpos],
td[rwpos], # Peak positions guessed from the wavelet's (scan nr)
NA, NA)) # Peak limits (scan nr)
peakinfo <- rbind(
peakinfo,
c(best.scale, best.scale.nr,
best.scale.pos, lwpos, rwpos))
## Peak positions guessed from the wavelet's
}
}
}
} # for (p in 1:length(wpeaksidx))
} # if (any(wpeaks))
## postprocessing
for (p in seq_len(nrow(peaks))) {
## find minima, assign rt and intensity values
if (integrate == 1) {
lm <- xcms:::descendMin(wCoefs[, peakinfo[p, "scaleNr"]],
istart = peakinfo[p, "scpos"])
gap <- all(d[lm[1]:lm[2]] == 0) # looks like we got stuck in a gap right in the middle of the peak
if ((lm[1] == lm[2]) || gap ) # fall-back
lm <- xcms:::descendMinTol(d, startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
} else {
lm <- xcms:::descendMinTol(d, startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
}
## Narrow down peak rt boundaries by removing values below cut-off
lm <- .narrow_rt_boundaries(lm, d)
lm_range <- lm[1]:lm[2]
pd <- d[lm_range]
peakrange <- td[lm]
peaks[p, "rtmin"] <- rt[peakrange[1]]
peaks[p, "rtmax"] <- rt[peakrange[2]]
peaks[p, "maxo"] <- max(pd)
pwid <- (rt[peakrange[2]] - rt[peakrange[1]]) /
(peakrange[2] - peakrange[1])
if (is.na(pwid))
pwid <- 1
peaks[p, "into"] <- pwid * sum(pd)
db <- pd - baseline
peaks[p, "intb"] <- pwid * sum(db[db>0])
peaks[p, "lmin"] <- lm[1]
peaks[p, "lmax"] <- lm[2]
if (fitgauss) {
## perform gaussian fits, use wavelets for inital parameters
td_lm <- td[lm_range]
md <- max(pd)
d1 <- pd / md ## normalize data for gaussian error calc.
pgauss <- fitGauss(td_lm, pd,
pgauss = list(mu = peaks[p, "scpos"],
sigma = peaks[p, "scmax"] -
peaks[p, "scmin"],
h = peaks[p, "maxo"]))
rtime <- peaks[p, "scpos"]
if (!any(is.na(pgauss)) && all(pgauss > 0)) {
gtime <- td[match(round(pgauss$mu), td)]
if (!is.na(gtime)) {
rtime <- gtime
peaks[p, "mu"] <- pgauss$mu
peaks[p, "sigma"] <- pgauss$sigma
peaks[p, "h"] <- pgauss$h
peaks[p,"egauss"] <- sqrt(
(1 / length(td_lm)) *
sum(((d1 - gauss(td_lm, pgauss$h / md,
pgauss$mu, pgauss$sigma))^2)))
}
}
peaks[p, "rt"] <- rt[rtime]
## avoid fitting side effects
if (peaks[p, "rt"] < peaks[p, "rtmin"])
peaks[p, "rt"] <- rt[peaks[p, "scpos"]]
} else {
peaks[p, "rt"] <- rt[peaks[p, "scpos"]]
}
} # end for (p in seq_len(nrow(peaks)))
peaks <- joinOverlappingPeaks(td, d, otd, rep(1, length(otd)), od, rt,
scan.range, peaks, maxGaussOverlap,
mzCenterFun = mzCenter.wMean)
if (!is.null(peaks))
peaklist[[length(peaklist) + 1]] <- peaks
} # end of for (i in seq_len(nrow(rois)))
if (length(peaklist) == 0) {
warning("No peaks found!")
if (verboseColumns)
nopeaks <- matrix(nrow = 0, ncol = peaks_ncols,
dimnames = list(character(), peaks_names))
else
nopeaks <- matrix(nrow = 0, ncol = length(basenames),
dimnames = list(character(), basenames))
return(nopeaks[, -(1:3), drop = FALSE])
}
p <- do.call(rbind, peaklist)
if (!verboseColumns)
p <- p[, basenames, drop = FALSE]
uorder <- order(p[, "into"], decreasing = TRUE)
pm <- p[, c("mzmin", "mzmax", "rtmin", "rtmax"), drop = FALSE]
uindex <- rectUnique(pm, uorder, mzdiff, ydiff = -0.00001) # allow adjacent peaks
unique(p[uindex, -(1:3), drop = FALSE])
}
#' @description
#'
#' Identify regions in the intensity vector in which we might expect a peak.
#' In contrast to the original `.Call("findmzROI")` we base the search
#' exclusively on the intensity values, first identifying local maxima in a
#' moving window approach based on the lower expected peak width
#' (`peakwidth[1]`) and subsequently defining regions with width equal to
#' `peakwidth[2]` centered around the local maxima.
#'
#' @param int `numeric` with the intensities. Should **not** contain `NA`s!
#'
#' @param rt `numeric` with the retention times.
#'
#' @param peakwidth `numeric(2)` with the lowe and upper bound for the expected
#' peak widths.
#'
#' @param prefilter `numeric(2)` (`c(k, I)`): only regions of interest with at
#' least `k` centroids with signal `>= I` are returned.
#'
#' @param noise `numeric(1)` defining the minimum required intensity for
#' centroids to be considered in the first analysis step.
#'
#' @return `matrix` with two columns `"scmin"`, `"scmax"` and `"sccent"` with
#' the index of (lower and upper) bound defining the region of interest and
#' the position of the center.
#'
#' @md
#'
#' @noRd
#'
#' @examples
#'
#' library(xcms)
#' od <- readMSData(system.file("cdf/KO/ko15.CDF", package = "faahKO"),
#' mode = "onDisk")
#'
#' ## Extract chromatographic data for a small m/z range
#' chr <- chromatogram(od, mz = c(272.1, 272.3))[1, 1]
#'
#' int <- intensity(chr)
#' int[is.na(int)] <- 0
#' rt <- rtime(chr)
#' .getRtROI(int, rt)
.getRtROI <- function(int, rt, peakwidth = c(20, 50), noise = 0,
prefilter = c(3, 100)) {
peakwidth <- range(peakwidth)
if (length(prefilter) != 2)
stop("'prefilter' has to be a 'numeric' of length 2")
int_len <- length(int)
if (int_len != length(rt))
stop("lengths of 'int' and 'rt' have to match")
## rt to halfWindowSize:
rt_step <- mean(diff(rt), na.rm = TRUE)
up_bound <- ceiling(peakwidth[2] / rt_step)
pk_idx <- which(MALDIquant:::.localMaxima(int, floor(peakwidth[1] /
rt_step)))
## First filter: int > noise
pk_idx <- pk_idx[int[pk_idx] >= noise]
if (!length(pk_idx))
return(matrix(ncol = 2, nrow = 0))
## Define the ROIs
scmin <- sapply(pk_idx - up_bound, max, y = 1)
scmax <- sapply(pk_idx + up_bound, min, y = int_len)
## Second filter: at least k values larger I
roi_idxs <- mapply(scmin, scmax, FUN = seq, SIMPLIFY = FALSE)
ok <- vapply(roi_idxs,
FUN = function(x, k, I) {
sum(int[x] >= I) >= k
},
FUN.VALUE = logical(1),
k = prefilter[1], I = prefilter[2],
USE.NAMES = FALSE)
if (any(ok))
cbind(scmin = scmin[ok], scmax = scmax[ok], sccent = pk_idx[ok])
else
matrix(ncol = 3, nrow = 0)
}
#' @description
#'
#' Simple helper function to narrow the identified chromatographic peak
#' boundaries excluding values that are below a certain threshold. This was
#' introduced to fix issue #300. Note: to be consistent with the original
#' code we *grow* the region on each side after subsetting.
#'
#' @param lm `integer(2)` with the lower and upper peak boundary.
#'
#' @param d `numeric` with the intensities (for baseline detection and wavelet
#' analysis).
#'
#' @param thresh `numeric(1)` defining the threshold below which values are
#' considered *zero*.
#'
#' @author Johannes Rainer
#'
#' @noRd
.narrow_rt_boundaries <- function(lm, d, thresh = 1) {
lm_seq <- lm[1]:lm[2]
above_thresh <- d[lm_seq] >= thresh
if (any(above_thresh)) {
## Expand by one on each side to be consistent with old code.
above_thresh <- above_thresh | c(above_thresh[-1], FALSE) |
c(FALSE, above_thresh[-length(above_thresh)])
lm <- range(lm_seq[above_thresh], na.rm = TRUE)
}
lm
}
Try the xcms package in your browser
Any scripts or data that you put into this service are public.
xcms documentation built on Nov. 8, 2020, 5:13 p.m.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
Defines functions .narrow_rt_boundaries .getRtROI peaksWithCentWave peaksWithMatchedFilter do_findChromPeaks_addPredIsoROIs_mod do_findChromPeaks_addPredIsoROIs do_findChromPeaks_centWaveWithPredIsoROIs do_findKalmanROI do_define_adducts do_define_isotopes .MSW_orig .MSW_orig do_findPeaks_MSW .matchedFilter_binYonX_no_iter .matchedFilter_orig do_findChromPeaks_matchedFilter do_findChromPeaks_massifquant .centWave_new .centWave_orig do_findChromPeaks_centWave
Documented in do_findChromPeaks_addPredIsoROIs do_findChromPeaks_centWave do_findChromPeaks_centWaveWithPredIsoROIs do_findChromPeaks_massifquant do_findChromPeaks_matchedFilter do_findPeaks_MSW peaksWithCentWave peaksWithMatchedFilter
## All low level (API) analysis functions for chromatographic peak detection
## should go in here.
#' @include c.R functions-binning.R cwTools.R
############################################################
## centWave
##
## Some notes on a potential speed up:
## Tried:
## o initialize peaks matrix in the inner loop instead of rbind: slower.
## o pre-initialize the peaks list; slower.
## o keep the peaks matrix small, add additional columns only if fitgauss or
## verboseColumns is TRUE.
## Conclusion:
## o speed improvement can only come from internal methods called withihn.
##
#' @title Core API function for centWave peak detection
#'
#' @description This function performs peak density and wavelet based
#' chromatographic peak detection for high resolution LC/MS data in centroid
#' mode [Tautenhahn 2008].
#'
#' @details
#'
#' This algorithm is most suitable for high resolution
#' LC/\{TOF,OrbiTrap,FTICR\}-MS data in centroid mode. In the first phase
#' the method identifies \emph{regions of interest} (ROIs) representing
#' mass traces that are characterized as regions with less than \code{ppm}
#' m/z deviation in consecutive scans in the LC/MS map. In detail, starting
#' with a single m/z, a ROI is extended if a m/z can be found in the next scan
#' (spectrum) for which the difference to the mean m/z of the ROI is smaller
#' than the user defined \code{ppm} of the m/z. The mean m/z of the ROI is then
#' updated considering also the newly included m/z value.
#'
#' These ROIs are then, after some cleanup, analyzed using continuous wavelet
#' transform (CWT) to locate chromatographic peaks on different scales. The
#' first analysis step is skipped, if regions of interest are passed with
#' the \code{roiList} parameter.
#'
#' @note The \emph{centWave} was designed to work on centroided mode, thus it
#' is expected that such data is presented to the function.
#'
#' This function exposes core chromatographic peak detection functionality
#' of the \emph{centWave} method. While this function can be called
#' directly, users will generally call the corresponding method for the
#' data object instead.
#'
#' @param mz Numeric vector with the individual m/z values from all scans/
#' spectra of one file/sample.
#'
#' @param int Numeric vector with the individual intensity values from all
#' scans/spectra of one file/sample.
#'
#' @param scantime Numeric vector of length equal to the number of
#' spectra/scans of the data representing the retention time of each scan.
#'
#' @param valsPerSpect Numeric vector with the number of values for each
#' spectrum.
#'
#' @param sleep \code{numeric(1)} defining the number of seconds to wait between
#' iterations. Defaults to \code{sleep = 0}. If \code{> 0} a plot is
#' generated visualizing the identified chromatographic peak. Note: this
#' argument is for backward compatibility only and will be removed in
#' future.
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @family core peak detection functions
#'
#' @references
#' Ralf Tautenhahn, Christoph B\"{o}ttcher, and Steffen Neumann "Highly
#' sensitive feature detection for high resolution LC/MS"
#' \emph{BMC Bioinformatics} 2008, 9:504
#'
#' @return
#' A matrix, each row representing an identified chromatographic peak,
#' with columns:
#' \describe{
#'
#' \item{mz}{Intensity weighted mean of m/z values of the peak across
#' scans.}
#' \item{mzmin}{Minimum m/z of the peak.}
#' \item{mzmax}{Maximum m/z of the peak.}
#' \item{rt}{Retention time of the peak's midpoint.}
#' \item{rtmin}{Minimum retention time of the peak.}
#' \item{rtmax}{Maximum retention time of the peak.}
#' \item{into}{Integrated (original) intensity of the peak.}
#' \item{intb}{Per-peak baseline corrected integrated peak intensity.}
#' \item{maxo}{Maximum intensity of the peak.}
#' \item{sn}{Signal to noise ratio, defined as \code{(maxo - baseline)/sd},
#' \code{sd} being the standard deviation of local chromatographic noise.}
#' \item{egauss}{RMSE of Gaussian fit.}
#' }
#' Additional columns for \code{verboseColumns = TRUE}:
#' \describe{
#'
#' \item{mu}{Gaussian parameter mu.}
#' \item{sigma}{Gaussian parameter sigma.}
#' \item{h}{Gaussian parameter h.}
#' \item{f}{Region number of the m/z ROI where the peak was localized.}
#' \item{dppm}{m/z deviation of mass trace across scans in ppm.}
#' \item{scale}{Scale on which the peak was localized.}
#' \item{scpos}{Peak position found by wavelet analysis (scan number).}
#' \item{scmin}{Left peak limit found by wavelet analysis (scan number).}
#' \item{scmax}{Right peak limit found by wavelet analysis (scan numer).}
#' }
#'
#' @author Ralf Tautenhahn, Johannes Rainer
#'
#' @seealso \code{\link{centWave}} for the standard user interface method.
#'
#' @examples
#' ## Load the test file
#' data(faahko_sub)
#' ## Update the path to the files for the local system
#' dirname(faahko_sub) <- system.file("cdf/KO", package = "faahKO")
#'
#' ## Subset to one file and restrict to a certain retention time range
#' data <- filterRt(filterFile(faahko_sub, 1), c(2500, 3000))
#'
#' ## Get m/z and intensity values
#' mzs <- mz(data)
#' ints <- intensity(data)
#'
#' ## Define the values per spectrum:
#' valsPerSpect <- lengths(mzs)
#'
#' ## Calling the function. We're using a large value for noise and prefilter
#' ## to speed up the call in the example - in a real use case we would either
#' ## set the value to a reasonable value or use the default value.
#' res <- do_findChromPeaks_centWave(mz = unlist(mzs), int = unlist(ints),
#' scantime = rtime(data), valsPerSpect = valsPerSpect, noise = 10000,
#' prefilter = c(3, 10000))
#' head(res)
do_findChromPeaks_centWave <- function(mz, int, scantime, valsPerSpect,
ppm = 25,
peakwidth = c(20, 50),
snthresh = 10,
prefilter = c(3, 100),
mzCenterFun = "wMean",
integrate = 1,
mzdiff = -0.001,
fitgauss = FALSE,
noise = 0,
verboseColumns = FALSE,
roiList = list(),
firstBaselineCheck = TRUE,
roiScales = NULL,
sleep = 0,
extendLengthMSW = FALSE) {
if (getOption("originalCentWave", default = TRUE)) {
## message("DEBUG: using original centWave.")
.centWave_orig(mz = mz, int = int, scantime = scantime,
valsPerSpect = valsPerSpect, ppm = ppm, peakwidth = peakwidth,
snthresh = snthresh, prefilter = prefilter,
mzCenterFun = mzCenterFun, integrate = integrate,
mzdiff = mzdiff, fitgauss = fitgauss, noise = noise,
verboseColumns = verboseColumns, roiList = roiList,
firstBaselineCheck = firstBaselineCheck,
roiScales = roiScales, sleep = sleep,
extendLengthMSW = extendLengthMSW)
} else {
## message("DEBUG: using modified centWave.")
.centWave_new(mz = mz, int = int, scantime = scantime,
valsPerSpect = valsPerSpect, ppm = ppm, peakwidth = peakwidth,
snthresh = snthresh, prefilter = prefilter,
mzCenterFun = mzCenterFun, integrate = integrate,
mzdiff = mzdiff, fitgauss = fitgauss, noise = noise,
verboseColumns = verboseColumns, roiList = roiList,
firstBaselineCheck = firstBaselineCheck,
roiScales = roiScales, sleep = sleep)
}
}
############################################################
## ORIGINAL code from xcms_1.49.7
.centWave_orig <- function(mz, int, scantime, valsPerSpect,
ppm = 25, peakwidth = c(20,50), snthresh = 10,
prefilter = c(3,100), mzCenterFun = "wMean",
integrate = 1, mzdiff = -0.001, fitgauss = FALSE,
noise = 0, ## noise.local=TRUE,
sleep = 0, verboseColumns = FALSE, roiList = list(),
firstBaselineCheck = TRUE, roiScales = NULL,
extendLengthMSW = FALSE) {
## Input argument checking.
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if (length(mz) != length(int) | length(valsPerSpect) != length(scantime)
| length(mz) != sum(valsPerSpect))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
scanindex <- valueCount2ScanIndex(valsPerSpect) ## Get index vector for C calls
if (!is.double(mz))
mz <- as.double(mz)
if (!is.double(int))
int <- as.double(int)
## Fix the mzCenterFun
mzCenterFun <- paste("mzCenter",
gsub(mzCenterFun, pattern = "mzCenter.",
replacement = "", fixed = TRUE), sep=".")
if (!exists(mzCenterFun, mode="function"))
stop("Function '", mzCenterFun, "' not defined !")
if (!is.logical(firstBaselineCheck))
stop("Parameter 'firstBaselineCheck' should be logical!")
if (length(firstBaselineCheck) != 1)
stop("Parameter 'firstBaselineCheck' should be a single logical !")
if (length(roiScales) > 0)
if (length(roiScales) != length(roiList) | !is.numeric(roiScales))
stop("If provided, parameter 'roiScales' has to be a numeric with",
" length equal to the length of 'roiList'!")
## if (!is.null(roiScales)) {
## if (!is.numeric(roiScales) | length(roiScales) != length(roiList))
## stop("Parameter 'roiScales' has to be a numeric of length equal to",
## " parameter 'roiList'!")
##}
basenames <- c("mz", "mzmin", "mzmax", "rt", "rtmin", "rtmax",
"into", "intb", "maxo", "sn")
verbosenames <- c("egauss", "mu", "sigma", "h", "f", "dppm", "scale",
"scpos", "scmin", "scmax", "lmin", "lmax")
## Peak width: seconds to scales
scalerange <- round((peakwidth / mean(diff(scantime))) / 2)
if (length(z <- which(scalerange == 0)))
scalerange <- scalerange[-z]
if (length(scalerange) < 1) {
warning("No scales? Please check peak width!")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
return(invisible(nopeaks))
}
if (length(scalerange) > 1)
scales <- seq(from = scalerange[1], to = scalerange[2], by = 2)
else
scales <- scalerange
minPeakWidth <- scales[1]
noiserange <- c(minPeakWidth * 3, max(scales) * 3)
maxGaussOverlap <- 0.5
minPtsAboveBaseLine <- max(4, minPeakWidth - 2)
minCentroids <- minPtsAboveBaseLine
scRangeTol <- maxDescOutlier <- floor(minPeakWidth / 2)
scanrange <- c(1, length(scantime))
## If no ROIs are supplied then search for them.
if (length(roiList) == 0) {
message("Detecting mass traces at ", ppm, " ppm ... ", appendLF = FALSE)
## flush.console();
## We're including the findmzROI code in this function to reduce
## the need to copy objects etc.
## We could also sort the data by m/z anyway; wouldn't need that
## much time. Once we're using classes from MSnbase we can be
## sure that values are correctly sorted.
withRestarts(
tryCatch({
tmp <- capture.output(
roiList <- .Call("findmzROI",
mz, int, scanindex,
as.double(c(0.0, 0.0)),
as.integer(scanrange),
as.integer(length(scantime)),
as.double(ppm * 1e-6),
as.integer(minCentroids),
as.integer(prefilter),
as.integer(noise),
PACKAGE ='xcms' )
)
},
error = function(e){
if (grepl("m/z sort assumption violated !", e$message)) {
invokeRestart("fixSort")
} else {
simpleError(e)
}
}),
fixSort = function() {
## Force ordering of values within spectrum by mz:
## o split values into a list -> mz per spectrum, intensity per
## spectrum.
## o define the ordering.
## o re-order the mz and intensity and unlist again.
## Note: the Rle split is faster than the "conventional" factor split.
splitF <- Rle(1:length(valsPerSpect), valsPerSpect)
mzl <- as.list(S4Vectors::split(mz, f = splitF))
oidx <- lapply(mzl, order)
mz <<- unlist(mapply(mzl, oidx, FUN = function(y, z) {
return(y[z])
}, SIMPLIFY = FALSE, USE.NAMES = FALSE), use.names = FALSE)
int <<- unlist(mapply(as.list(split(int, f = splitF)), oidx,
FUN=function(y, z) {
return(y[z])
}, SIMPLIFY = FALSE, USE.NAMES = FALSE),
use.names = FALSE)
rm(mzl)
rm(splitF)
tmp <- capture.output(
roiList <<- .Call("findmzROI",
mz, int, scanindex,
as.double(c(0.0, 0.0)),
as.integer(scanrange),
as.integer(length(scantime)),
as.double(ppm * 1e-6),
as.integer(minCentroids),
as.integer(prefilter),
as.integer(noise),
PACKAGE ='xcms' )
)
}
)
message("OK")
## ROI.list <- findmzROI(object,scanrange=scanrange,dev=ppm * 1e-6,minCentroids=minCentroids, prefilter=prefilter, noise=noise)
if (length(roiList) == 0) {
warning("No ROIs found! \n")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
return(invisible(nopeaks))
}
}
## Second stage: process the ROIs
peaklist <- list()
Nscantime <- length(scantime)
lf <- length(roiList)
## cat('\n Detecting chromatographic peaks ... \n % finished: ')
## lp <- -1
message("Detecting chromatographic peaks in ", length(roiList),
" regions of interest ...", appendLF = FALSE)
for (f in 1:lf) {
## ## Show progress
## perc <- round((f/lf) * 100)
## if ((perc %% 10 == 0) && (perc != lp))
## {
## cat(perc," ",sep="");
## lp <- perc;
## }
## flush.console()
feat <- roiList[[f]]
N <- feat$scmax - feat$scmin + 1
peaks <- peakinfo <- NULL
mzrange <- c(feat$mzmin, feat$mzmax)
sccenter <- feat$scmin[1] + floor(N/2) - 1
scrange <- c(feat$scmin, feat$scmax)
## scrange + noiserange, used for baseline detection and wavelet analysis
sr <- c(max(scanrange[1], scrange[1] - max(noiserange)),
min(scanrange[2], scrange[2] + max(noiserange)))
eic <- .Call("getEIC", mz, int, scanindex, as.double(mzrange),
as.integer(sr), as.integer(length(scanindex)),
PACKAGE = "xcms")
## eic <- rawEIC(object,mzrange=mzrange,scanrange=sr)
d <- eic$intensity
td <- sr[1]:sr[2]
scan.range <- c(sr[1], sr[2])
## original mzROI range
idxs <- which(eic$scan %in% seq(scrange[1], scrange[2]))
mzROI.EIC <- list(scan=eic$scan[idxs], intensity=eic$intensity[idxs])
## mzROI.EIC <- rawEIC(object,mzrange=mzrange,scanrange=scrange)
omz <- .Call("getMZ", mz, int, scanindex, as.double(mzrange),
as.integer(scrange), as.integer(length(scantime)),
PACKAGE = 'xcms')
## omz <- rawMZ(object,mzrange=mzrange,scanrange=scrange)
if (all(omz == 0)) {
warning("centWave: no peaks found in ROI.")
next
}
od <- mzROI.EIC$intensity
otd <- mzROI.EIC$scan
if (all(od == 0)) {
warning("centWave: no peaks found in ROI.")
next
}
## scrange + scRangeTol, used for gauss fitting and continuous
## data above 1st baseline detection
ftd <- max(td[1], scrange[1] - scRangeTol) : min(td[length(td)],
scrange[2] + scRangeTol)
fd <- d[match(ftd, td)]
## 1st type of baseline: statistic approach
if (N >= 10*minPeakWidth) {
## in case of very long mass trace use full scan range
## for baseline detection
noised <- .Call("getEIC", mz, int, scanindex, as.double(mzrange),
as.integer(scanrange), as.integer(length(scanindex)),
PACKAGE="xcms")$intensity
## noised <- rawEIC(object,mzrange=mzrange,scanrange=scanrange)$intensity
} else {
noised <- d
}
## 90% trimmed mean as first baseline guess
noise <- estimateChromNoise(noised, trim = 0.05,
minPts = 3 * minPeakWidth)
## any continuous data above 1st baseline ?
if (firstBaselineCheck &
!continuousPtsAboveThreshold(fd, threshold = noise,
num = minPtsAboveBaseLine))
next
## 2nd baseline estimate using not-peak-range
lnoise <- getLocalNoiseEstimate(d, td, ftd, noiserange, Nscantime,
threshold = noise,
num = minPtsAboveBaseLine)
## Final baseline & Noise estimate
baseline <- max(1, min(lnoise[1], noise))
sdnoise <- max(1, lnoise[2])
sdthr <- sdnoise * snthresh
## is there any data above S/N * threshold ?
if (!(any(fd - baseline >= sdthr)))
next
wCoefs <- MSW.cwt(d, scales = scales, wavelet = 'mexh',
extendLengthMSW = extendLengthMSW)
if (!(!is.null(dim(wCoefs)) && any(wCoefs- baseline >= sdthr)))
next
if (td[length(td)] == Nscantime) ## workaround, localMax fails otherwise
wCoefs[nrow(wCoefs),] <- wCoefs[nrow(wCoefs) - 1, ] * 0.99
localMax <- MSW.getLocalMaximumCWT(wCoefs)
rL <- MSW.getRidge(localMax)
wpeaks <- sapply(rL,
function(x) {
w <- min(1:length(x),ncol(wCoefs))
any(wCoefs[x,w]- baseline >= sdthr)
})
if (any(wpeaks)) {
wpeaksidx <- which(wpeaks)
## check each peak in ridgeList
for (p in 1:length(wpeaksidx)) {
opp <- rL[[wpeaksidx[p]]]
pp <- unique(opp)
if (length(pp) >= 1) {
dv <- td[pp] %in% ftd
if (any(dv)) { ## peaks in orig. data range
## Final S/N check
if (any(d[pp[dv]]- baseline >= sdthr)) {
## if(!is.null(roiScales)) {
## allow roiScales to be a numeric of length 0
if(length(roiScales) > 0) {
## use given scale
best.scale.nr <- which(scales == roiScales[[f]])
if(best.scale.nr > length(opp))
best.scale.nr <- length(opp)
} else {
## try to decide which scale describes the peak best
inti <- numeric(length(opp))
irange <- rep(ceiling(scales[1]/2), length(opp))
for (k in 1:length(opp)) {
kpos <- opp[k]
r1 <- ifelse(kpos - irange[k] > 1,
kpos-irange[k], 1)
r2 <- ifelse(kpos + irange[k] < length(d),
kpos + irange[k], length(d))
inti[k] <- sum(d[r1:r2])
}
maxpi <- which.max(inti)
if (length(maxpi) > 1) {
m <- wCoefs[opp[maxpi], maxpi]
bestcol <- which(m == max(m),
arr.ind = TRUE)[2]
best.scale.nr <- maxpi[bestcol]
} else best.scale.nr <- maxpi
}
best.scale <- scales[best.scale.nr]
best.scale.pos <- opp[best.scale.nr]
pprange <- min(pp):max(pp)
## maxint <- max(d[pprange])
lwpos <- max(1,best.scale.pos - best.scale)
rwpos <- min(best.scale.pos + best.scale, length(td))
p1 <- match(td[lwpos], otd)[1]
p2 <- match(td[rwpos], otd)
p2 <- p2[length(p2)]
if (is.na(p1)) p1 <- 1
if (is.na(p2)) p2 <- N
mz.value <- omz[p1:p2]
mz.int <- od[p1:p2]
maxint <- max(mz.int)
## re-calculate m/z value for peak range
mzrange <- range(mz.value)
mzmean <- do.call(mzCenterFun,
list(mz = mz.value,
intensity = mz.int))
## Compute dppm only if needed
dppm <- NA
if (verboseColumns) {
if (length(mz.value) >= (minCentroids + 1)) {
dppm <- round(min(running(abs(diff(mz.value)) /
(mzrange[2] * 1e-6),
fun = max,
width = minCentroids)))
} else {
dppm <- round((mzrange[2] - mzrange[1]) /
(mzrange[2] * 1e-6))
}
}
peaks <- rbind(peaks,
c(mzmean,mzrange, ## mz
NA, NA, NA, ## rt, rtmin, rtmax,
NA, ## intensity (sum)
NA, ## intensity (-bl)
maxint, ## max intensity
round((maxint - baseline) / sdnoise), ## S/N Ratio
NA, ## Gaussian RMSE
NA,NA,NA, ## Gaussian Parameters
f, ## ROI Position
dppm, ## max. difference between the [minCentroids] peaks in ppm
best.scale, ## Scale
td[best.scale.pos],
td[lwpos],
td[rwpos], ## Peak positions guessed from the wavelet's (scan nr)
NA, NA)) ## Peak limits (scan nr)
peakinfo <- rbind(peakinfo,
c(best.scale, best.scale.nr,
best.scale.pos, lwpos, rwpos))
## Peak positions guessed from the wavelet's
}
}
}
} ##for
} ## if
## postprocessing
if (!is.null(peaks)) {
colnames(peaks) <- c(basenames, verbosenames)
colnames(peakinfo) <- c("scale", "scaleNr", "scpos",
"scmin", "scmax")
for (p in 1:dim(peaks)[1]) {
## find minima (peak boundaries), assign rt and intensity values
if (integrate == 1) {
lm <- descendMin(wCoefs[, peakinfo[p, "scaleNr"]],
istart = peakinfo[p, "scpos"])
gap <- all(d[lm[1]:lm[2]] == 0) # looks like we got stuck in a gap right in the middle of the peak
if ((lm[1] == lm[2]) || gap) # fall-back
lm <- descendMinTol(
d, startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
} else {
lm <- descendMinTol(d, startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
}
## Narrow peak rt boundaries by removing values below threshold
lm <- .narrow_rt_boundaries(lm, d)
lm_seq <- lm[1]:lm[2]
pd <- d[lm_seq]
peakrange <- td[lm]
peaks[p, "rtmin"] <- scantime[peakrange[1]]
peaks[p, "rtmax"] <- scantime[peakrange[2]]
peaks[p, "maxo"] <- max(pd)
pwid <- (scantime[peakrange[2]] - scantime[peakrange[1]]) /
(peakrange[2] - peakrange[1])
if (is.na(pwid))
pwid <- 1
peaks[p, "into"] <- pwid * sum(pd)
db <- pd - baseline
peaks[p, "intb"] <- pwid * sum(db[db > 0])
peaks[p, "lmin"] <- lm[1]
peaks[p, "lmax"] <- lm[2]
if (fitgauss) {
## perform gaussian fits, use wavelets for inital parameters
td_lm <- td[lm_seq]
md <- max(pd)
d1 <- pd / md ## normalize data for gaussian error calc.
pgauss <- fitGauss(td_lm, pd,
pgauss = list(mu = peaks[p, "scpos"],
sigma = peaks[p, "scmax"] -
peaks[p, "scmin"],
h = peaks[p, "maxo"]))
rtime <- peaks[p, "scpos"]
if (!any(is.na(pgauss)) && all(pgauss > 0)) {
gtime <- td[match(round(pgauss$mu), td)]
if (!is.na(gtime)) {
rtime <- gtime
peaks[p, "mu"] <- pgauss$mu
peaks[p, "sigma"] <- pgauss$sigma
peaks[p, "h"] <- pgauss$h
peaks[p,"egauss"] <- sqrt(
(1 / length(td_lm)) *
sum(((d1 - gauss(td_lm, pgauss$h / md,
pgauss$mu, pgauss$sigma))^2)))
}
}
peaks[p, "rt"] <- scantime[rtime]
## avoid fitting side effects
if (peaks[p, "rt"] < peaks[p, "rtmin"])
peaks[p, "rt"] <- scantime[peaks[p, "scpos"]]
} else
peaks[p, "rt"] <- scantime[peaks[p, "scpos"]]
}
peaks <- joinOverlappingPeaks(td, d, otd, omz, od, scantime,
scan.range, peaks, maxGaussOverlap,
mzCenterFun = mzCenterFun)
}
## BEGIN - plotting/sleep
if ((sleep >0) && (!is.null(peaks))) {
tdp <- scantime[td]; trange <- range(tdp)
egauss <- paste(round(peaks[,"egauss"],3),collapse=", ")
cdppm <- paste(peaks[,"dppm"],collapse=", ")
csn <- paste(peaks[,"sn"],collapse=", ")
par(bg = "white")
l <- layout(matrix(c(1,2,3),nrow=3,ncol=1,byrow=T),heights=c(.5,.75,2));
par(mar= c(2, 4, 4, 2) + 0.1)
## plotRaw(object,mzrange=mzrange,rtrange=trange,log=TRUE,title='')
## Do plotRaw manually.
raw_mat <- .rawMat(mz = mz, int = int, scantime = scantime,
valsPerSpect = valsPerSpect, mzrange = mzrange,
rtrange = rtrange, log = TRUE)
if (nrow(raw_mat) > 0) {
y <- raw_mat[, "intensity"]
ylim <- range(y)
y <- y / ylim[2]
colorlut <- terrain.colors(16)
col <- colorlut[y * 15 + 1]
plot(raw_mat[, "time"], raw_mat[, "mz"], pch = 20, cex = .5,
main = "", xlab = "Seconds", ylab = "m/z", col = col,
xlim = trange)
} else {
plot(c(NA, NA), main = "", xlab = "Seconds", ylab = "m/z",
xlim = trange, ylim = mzrange)
}
## done
title(main=paste(f,': ', round(mzrange[1],4),' - ',round(mzrange[2],4),' m/z , dppm=',cdppm,', EGauss=',egauss ,', S/N =',csn,sep=''))
par(mar= c(1, 4, 1, 2) + 0.1)
image(y=scales[1:(dim(wCoefs)[2])],z=wCoefs,col=terrain.colors(256),xaxt='n',ylab='CWT coeff.')
par(mar= c(4, 4, 1, 2) + 0.1)
plot(tdp,d,ylab='Intensity',xlab='Scan Time');lines(tdp,d,lty=2)
lines(scantime[otd],od,lty=2,col='blue') ## original mzbox range
abline(h=baseline,col='green')
bwh <- length(sr[1]:sr[2]) - length(baseline)
if (odd(bwh)) {bwh1 <- floor(bwh/2); bwh2 <- bwh1+1} else {bwh1<-bwh2<-bwh/2}
if (any(!is.na(peaks[,"scpos"])))
{ ## plot centers and width found through wavelet analysis
abline(v=scantime[na.omit(peaks[(peaks[,"scpos"] >0),"scpos"])],col='red')
}
abline(v=na.omit(c(peaks[,"rtmin"],peaks[,"rtmax"])),col='green',lwd=1)
if (fitgauss) {
tdx <- seq(min(td),max(td),length.out=200)
tdxp <- seq(trange[1],trange[2],length.out=200)
fitted.peaks <- which(!is.na(peaks[,"mu"]))
for (p in fitted.peaks)
{ ## plot gaussian fits
yg<-gauss(tdx,peaks[p,"h"],peaks[p,"mu"],peaks[p,"sigma"])
lines(tdxp,yg,col='blue')
}
}
Sys.sleep(sleep)
}
## -- END plotting/sleep
if (!is.null(peaks)) {
peaklist[[length(peaklist) + 1]] <- peaks
}
} ## f
if (length(peaklist) == 0) {
warning("No peaks found!")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
message(" FAIL: none found!")
return(nopeaks)
}
p <- do.call(rbind, peaklist)
if (!verboseColumns)
p <- p[, basenames, drop = FALSE]
uorder <- order(p[, "into"], decreasing = TRUE)
pm <- as.matrix(p[,c("mzmin", "mzmax", "rtmin", "rtmax"), drop = FALSE])
uindex <- rectUnique(pm, uorder, mzdiff, ydiff = -0.00001) ## allow adjacent peaks
pr <- p[uindex, , drop = FALSE]
message(" OK: ", nrow(pr), " found.")
return(pr)
}
## This version fixes issue #135, i.e. that the peak signal is integrated based
## on the mzrange of the ROI and not of the actually reported peak.
## Issue #136.
##
## What's different to the original version?
##
## 1) The mz range of the peaks is calculated only using mz values with a
## measured intensity. This avoids mz ranges from 0 to max mz of the peak,
## with the mz=0 corresponding actually to scans in which no intensity was
## measured. Search for "@MOD1" to jump to the respective code.
##
## 2) The intensities for the peak are reloaded with the refined mz range during
## the postprocessing. Search for "@MOD2" to jump to the respective code.
##
## What I don't like:
## o Might be better if the getEIC and getMZ C functions returned NA instead of 0
## if nothing was measured.
## o The joinOverlappingPeaks is still calculated using the variable "d" which
## contains all intensities from the ROI - might actually not be too bad
## though.
.centWave_new <- function(mz, int, scantime, valsPerSpect,
ppm = 25, peakwidth = c(20,50), snthresh = 10,
prefilter = c(3,100), mzCenterFun = "wMean",
integrate = 1, mzdiff = -0.001, fitgauss = FALSE,
noise = 0, ## noise.local=TRUE,
sleep = 0, verboseColumns = FALSE, roiList = list(),
firstBaselineCheck = TRUE, roiScales = NULL) {
if (sleep)
warning("Parameter 'sleep' is defunct")
## Input argument checking.
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if (length(mz) != length(int) | length(valsPerSpect) != length(scantime)
| length(mz) != sum(valsPerSpect))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
scanindex <- valueCount2ScanIndex(valsPerSpect) ## Get index vector for C calls
if (!is.double(mz))
mz <- as.double(mz)
if (!is.double(int))
int <- as.double(int)
## Fix the mzCenterFun
mzCenterFun <- paste("mzCenter",
gsub(mzCenterFun, pattern = "mzCenter.",
replacement = "", fixed = TRUE), sep=".")
if (!exists(mzCenterFun, mode="function"))
stop("Function '", mzCenterFun, "' not defined !")
if (!is.logical(firstBaselineCheck))
stop("Parameter 'firstBaselineCheck' should be logical!")
if (length(firstBaselineCheck) != 1)
stop("Parameter 'firstBaselineCheck' should be a single logical !")
if (length(roiScales) > 0)
if (length(roiScales) != length(roiList) | !is.numeric(roiScales))
stop("If provided, parameter 'roiScales' has to be a numeric with",
" length equal to the length of 'roiList'!")
basenames <- c("mz", "mzmin", "mzmax", "rt", "rtmin", "rtmax",
"into", "intb", "maxo", "sn")
verbosenames <- c("egauss", "mu", "sigma", "h", "f", "dppm", "scale",
"scpos", "scmin", "scmax", "lmin", "lmax")
## Peak width: seconds to scales
scalerange <- round((peakwidth / mean(diff(scantime))) / 2)
if (length(z <- which(scalerange == 0)))
scalerange <- scalerange[-z]
if (length(scalerange) < 1) {
warning("No scales? Please check peak width!")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
return(invisible(nopeaks))
}
if (length(scalerange) > 1)
scales <- seq(from = scalerange[1], to = scalerange[2], by = 2)
else
scales <- scalerange
minPeakWidth <- scales[1]
noiserange <- c(minPeakWidth * 3, max(scales) * 3)
maxGaussOverlap <- 0.5
minPtsAboveBaseLine <- max(4, minPeakWidth - 2)
minCentroids <- minPtsAboveBaseLine
scRangeTol <- maxDescOutlier <- floor(minPeakWidth / 2)
scanrange <- c(1, length(scantime))
## If no ROIs are supplied then search for them.
if (length(roiList) == 0) {
message("Detecting mass traces at ", ppm, " ppm ... ", appendLF = FALSE)
## flush.console();
## We're including the findmzROI code in this function to reduce
## the need to copy objects etc.
## We could also sort the data by m/z anyway; wouldn't need that
## much time. Once we're using classes from MSnbase we can be
## sure that values are correctly sorted.
withRestarts(
tryCatch({
tmp <- capture.output(
roiList <- .Call("findmzROI",
mz, int, scanindex,
as.double(c(0.0, 0.0)),
as.integer(scanrange),
as.integer(length(scantime)),
as.double(ppm * 1e-6),
as.integer(minCentroids),
as.integer(prefilter),
as.integer(noise),
PACKAGE ='xcms' )
)
},
error = function(e){
if (grepl("m/z sort assumption violated !", e$message)) {
invokeRestart("fixSort")
} else {
simpleError(e)
}
}),
fixSort = function() {
## Force ordering of values within spectrum by mz:
## o split values into a list -> mz per spectrum, intensity per
## spectrum.
## o define the ordering.
## o re-order the mz and intensity and unlist again.
## Note: the Rle split is faster than the "conventional" factor split.
splitF <- Rle(1:length(valsPerSpect), valsPerSpect)
mzl <- as.list(S4Vectors::split(mz, f = splitF))
oidx <- lapply(mzl, order)
mz <<- unlist(mapply(mzl, oidx, FUN = function(y, z) {
return(y[z])
}, SIMPLIFY = FALSE, USE.NAMES = FALSE), use.names = FALSE)
int <<- unlist(mapply(as.list(split(int, f = splitF)), oidx,
FUN=function(y, z) {
return(y[z])
}, SIMPLIFY = FALSE, USE.NAMES = FALSE),
use.names = FALSE)
rm(mzl)
rm(splitF)
tmp <- capture.output(
roiList <<- .Call("findmzROI",
mz, int, scanindex,
as.double(c(0.0, 0.0)),
as.integer(scanrange),
as.integer(length(scantime)),
as.double(ppm * 1e-6),
as.integer(minCentroids),
as.integer(prefilter),
as.integer(noise),
PACKAGE ='xcms' )
)
}
)
message("OK")
if (length(roiList) == 0) {
warning("No ROIs found! \n")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
return(invisible(nopeaks))
}
}
## Second stage: process the ROIs
peaklist <- list()
Nscantime <- length(scantime)
lf <- length(roiList)
## cat('\n Detecting chromatographic peaks ... \n % finished: ')
## lp <- -1
message("Detecting chromatographic peaks in ", length(roiList),
" regions of interest ...", appendLF = FALSE)
for (f in 1:lf) {
## cat("\nProcess roi ", f, "\n")
feat <- roiList[[f]]
N <- feat$scmax - feat$scmin + 1
peaks <- peakinfo <- NULL
mzrange <- c(feat$mzmin, feat$mzmax)
mzrange_ROI <- mzrange
sccenter <- feat$scmin[1] + floor(N/2) - 1
scrange <- c(feat$scmin, feat$scmax)
## scrange + noiserange, used for baseline detection and wavelet analysis
sr <- c(max(scanrange[1], scrange[1] - max(noiserange)),
min(scanrange[2], scrange[2] + max(noiserange)))
eic <- .Call("getEIC", mz, int, scanindex, as.double(mzrange),
as.integer(sr), as.integer(length(scanindex)),
PACKAGE = "xcms")
d <- eic$intensity
td <- sr[1]:sr[2]
scan.range <- c(sr[1], sr[2])
## original mzROI range
idxs <- which(eic$scan %in% seq(scrange[1], scrange[2]))
mzROI.EIC <- list(scan=eic$scan[idxs], intensity=eic$intensity[idxs])
omz <- .Call("getMZ", mz, int, scanindex, as.double(mzrange),
as.integer(scrange), as.integer(length(scantime)),
PACKAGE = 'xcms')
if (all(omz == 0)) {
warning("centWave: no peaks found in ROI.")
next
}
od <- mzROI.EIC$intensity
otd <- mzROI.EIC$scan
if (all(od == 0)) {
warning("centWave: no peaks found in ROI.")
next
}
## scrange + scRangeTol, used for gauss fitting and continuous
## data above 1st baseline detection
ftd <- max(td[1], scrange[1] - scRangeTol) : min(td[length(td)],
scrange[2] + scRangeTol)
fd <- d[match(ftd, td)]
## 1st type of baseline: statistic approach
if (N >= 10 * minPeakWidth) {
## in case of very long mass trace use full scan range
## for baseline detection
noised <- .Call("getEIC", mz, int, scanindex, as.double(mzrange),
as.integer(scanrange), as.integer(length(scanindex)),
PACKAGE="xcms")$intensity
} else {
noised <- d
}
## 90% trimmed mean as first baseline guess
noise <- estimateChromNoise(noised, trim = 0.05,
minPts = 3 * minPeakWidth)
## any continuous data above 1st baseline ?
if (firstBaselineCheck &
!continuousPtsAboveThreshold(fd, threshold = noise,
num = minPtsAboveBaseLine))
next
## 2nd baseline estimate using not-peak-range
lnoise <- getLocalNoiseEstimate(d, td, ftd, noiserange, Nscantime,
threshold = noise,
num = minPtsAboveBaseLine)
## Final baseline & Noise estimate
baseline <- max(1, min(lnoise[1], noise))
sdnoise <- max(1, lnoise[2])
sdthr <- sdnoise * snthresh
## is there any data above S/N * threshold ?
if (!(any(fd - baseline >= sdthr)))
next
wCoefs <- MSW.cwt(d, scales = scales, wavelet = 'mexh')
if (!(!is.null(dim(wCoefs)) && any(wCoefs- baseline >= sdthr)))
next
if (td[length(td)] == Nscantime) ## workaround, localMax fails otherwise
wCoefs[nrow(wCoefs),] <- wCoefs[nrow(wCoefs) - 1, ] * 0.99
localMax <- MSW.getLocalMaximumCWT(wCoefs)
rL <- MSW.getRidge(localMax)
wpeaks <- sapply(rL,
function(x) {
w <- min(1:length(x),ncol(wCoefs))
any(wCoefs[x,w]- baseline >= sdthr)
})
if (any(wpeaks)) {
wpeaksidx <- which(wpeaks)
## check each peak in ridgeList
for (p in 1:length(wpeaksidx)) {
opp <- rL[[wpeaksidx[p]]]
pp <- unique(opp)
if (length(pp) >= 1) {
dv <- td[pp] %in% ftd
if (any(dv)) { ## peaks in orig. data range
## Final S/N check
if (any(d[pp[dv]]- baseline >= sdthr)) {
## if(!is.null(roiScales)) {
## allow roiScales to be a numeric of length 0
if(length(roiScales) > 0) {
## use given scale
best.scale.nr <- which(scales == roiScales[[f]])
if(best.scale.nr > length(opp))
best.scale.nr <- length(opp)
} else {
## try to decide which scale describes the peak best
inti <- numeric(length(opp))
irange <- rep(ceiling(scales[1]/2), length(opp))
for (k in 1:length(opp)) {
kpos <- opp[k]
r1 <- ifelse(kpos - irange[k] > 1,
kpos-irange[k], 1)
r2 <- ifelse(kpos + irange[k] < length(d),
kpos + irange[k], length(d))
inti[k] <- sum(d[r1:r2])
}
maxpi <- which.max(inti)
if (length(maxpi) > 1) {
m <- wCoefs[opp[maxpi], maxpi]
bestcol <- which(m == max(m),
arr.ind = TRUE)[2]
best.scale.nr <- maxpi[bestcol]
} else best.scale.nr <- maxpi
}
best.scale <- scales[best.scale.nr]
best.scale.pos <- opp[best.scale.nr]
pprange <- min(pp):max(pp)
## maxint <- max(d[pprange])
lwpos <- max(1,best.scale.pos - best.scale)
rwpos <- min(best.scale.pos + best.scale, length(td))
p1 <- match(td[lwpos], otd)[1]
p2 <- match(td[rwpos], otd)
p2 <- p2[length(p2)]
## cat("p1: ", p1, " p2: ", p2, "\n")
if (is.na(p1)) p1 <- 1
if (is.na(p2)) p2 <- N
mz.value <- omz[p1:p2]
## cat("mz.value: ", paste0(mz.value, collapse = ", "),
## "\n")
mz.int <- od[p1:p2]
maxint <- max(mz.int)
## @MOD1: Remove mz values for which no intensity was
## measured. Would be better if getEIC returned NA
## if nothing was measured.
mzorig <- mz.value
mz.value <- mz.value[mz.int > 0]
mz.int <- mz.int[mz.int > 0]
## Call next to avoid reporting peaks without mz
## values (issue #165).
if (length(mz.value) == 0)
next
## cat("mz.value: ", paste0(mz.value, collapse = ", "),
## "\n")
## re-calculate m/z value for peak range
## cat("mzrange refined: [",
## paste0(mzrange, collapse = ", "), "]")
## hm, shouldn't we get rid of the mz = 0 here?
mzrange <- range(mz.value)
## cat(" -> [",
## paste0(mzrange, collapse = ", "), "]\n")
mzmean <- do.call(mzCenterFun,
list(mz = mz.value,
intensity = mz.int))
## Compute dppm only if needed
dppm <- NA
if (verboseColumns) {
if (length(mz.value) >= (minCentroids + 1)) {
dppm <- round(min(running(abs(diff(mz.value)) /
(mzrange[2] * 1e-6),
fun = max,
width = minCentroids)))
} else {
dppm <- round((mzrange[2] - mzrange[1]) /
(mzrange[2] * 1e-6))
}
}
peaks <- rbind(peaks,
c(mzmean,mzrange, ## mz
NA, NA, NA, ## rt, rtmin, rtmax,
NA, ## intensity (sum)
NA, ## intensity (-bl)
maxint, ## max intensity
round((maxint - baseline) / sdnoise), ## S/N Ratio
NA, ## Gaussian RMSE
NA,NA,NA, ## Gaussian Parameters
f, ## ROI Position
dppm, ## max. difference between the [minCentroids] peaks in ppm
best.scale, ## Scale
td[best.scale.pos],
td[lwpos],
td[rwpos], ## Peak positions guessed from the wavelet's (scan nr)
NA, NA)) ## Peak limits (scan nr)
peakinfo <- rbind(peakinfo,
c(best.scale, best.scale.nr,
best.scale.pos, lwpos, rwpos))
## Peak positions guessed from the wavelet's
}
}
}
} ##for
} ## if
## postprocessing
if (!is.null(peaks)) {
colnames(peaks) <- c(basenames, verbosenames)
colnames(peakinfo) <- c("scale", "scaleNr", "scpos",
"scmin", "scmax")
for (p in 1:dim(peaks)[1]) {
## @MOD2
## Fix for issue #135: reload the EIC data if the
## mzrange differs from that of the ROI, but only if the mz
## range of the peak is different from the one of the ROI.
mzr <- peaks[p, c("mzmin", "mzmax")]
if (any(mzr != mzrange_ROI)) {
eic <- .Call("getEIC", mz, int, scanindex,
as.double(mzr), as.integer(sr),
as.integer(length(scanindex)),
PACKAGE = "xcms")
current_ints <- eic$intensity
## Force re-loading also of a potential additional peak in
## the same ROI.
mzrange_ROI <- c(0, 0)
} else {
current_ints <- d
}
## find minima, assign rt and intensity values
if (integrate == 1) {
lm <- descendMin(wCoefs[, peakinfo[p,"scaleNr"]],
istart = peakinfo[p,"scpos"])
gap <- all(current_ints[lm[1]:lm[2]] == 0) ## looks like we got stuck in a gap right in the middle of the peak
if ((lm[1] == lm[2]) || gap )## fall-back
lm <- descendMinTol(current_ints,
startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
} else {
lm <- descendMinTol(current_ints,
startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
}
## Narrow peak rt boundaries by removing values below cut-off
lm <- .narrow_rt_boundaries(lm, d)
lm_seq <- lm[1]:lm[2]
pd <- current_ints[lm_seq]
peakrange <- td[lm]
peaks[p, "rtmin"] <- scantime[peakrange[1]]
peaks[p, "rtmax"] <- scantime[peakrange[2]]
peaks[p, "maxo"] <- max(pd)
pwid <- (scantime[peakrange[2]] - scantime[peakrange[1]]) /
(peakrange[2] - peakrange[1])
if (is.na(pwid))
pwid <- 1
peaks[p, "into"] <- pwid * sum(pd)
db <- pd - baseline
peaks[p, "intb"] <- pwid * sum(db[db > 0])
peaks[p, "lmin"] <- lm[1]
peaks[p, "lmax"] <- lm[2]
if (fitgauss) {
## perform gaussian fits, use wavelets for inital parameters
td_lm <- td[lm_seq]
md <- max(pd)
d1 <- pd / md ## normalize data for gaussian error calc.
pgauss <- fitGauss(td_lm, pd,
pgauss = list(mu = peaks[p, "scpos"],
sigma = peaks[p, "scmax"] -
peaks[p, "scmin"],
h = peaks[p, "maxo"]))
rtime <- peaks[p, "scpos"]
if (!any(is.na(pgauss)) && all(pgauss > 0)) {
gtime <- td[match(round(pgauss$mu), td)]
if (!is.na(gtime)) {
rtime <- gtime
peaks[p, "mu"] <- pgauss$mu
peaks[p, "sigma"] <- pgauss$sigma
peaks[p, "h"] <- pgauss$h
peaks[p,"egauss"] <- sqrt(
(1 / length(td_lm)) *
sum(((d1 - gauss(td_lm, pgauss$h / md,
pgauss$mu, pgauss$sigma))^2)))
}
}
peaks[p, "rt"] <- scantime[rtime]
## avoid fitting side effects
if (peaks[p, "rt"] < peaks[p, "rtmin"])
peaks[p, "rt"] <- scantime[peaks[p, "scpos"]]
} else
peaks[p, "rt"] <- scantime[peaks[p, "scpos"]]
}
## Use d here instead of current_ints
peaks <- joinOverlappingPeaks(td, d, otd, omz, od,
scantime, scan.range, peaks,
maxGaussOverlap,
mzCenterFun = mzCenterFun)
}
if (!is.null(peaks)) {
peaklist[[length(peaklist) + 1]] <- peaks
}
} ## f
if (length(peaklist) == 0) {
warning("No peaks found!")
if (verboseColumns) {
nopeaks <- matrix(nrow = 0, ncol = length(basenames) +
length(verbosenames))
colnames(nopeaks) <- c(basenames, verbosenames)
} else {
nopeaks <- matrix(nrow = 0, ncol = length(basenames))
colnames(nopeaks) <- c(basenames)
}
message(" FAIL: none found!")
return(nopeaks)
}
## cat("length peaklist: ", length(peaklist), "\n")
p <- do.call(rbind, peaklist)
if (!verboseColumns)
p <- p[, basenames, drop = FALSE]
return(p)
uorder <- order(p[, "into"], decreasing = TRUE)
pm <- as.matrix(p[,c("mzmin", "mzmax", "rtmin", "rtmax"), drop = FALSE])
uindex <- rectUnique(pm, uorder, mzdiff, ydiff = -0.00001) ## allow adjacent peaks
pr <- p[uindex, , drop = FALSE]
message(" OK: ", nrow(pr), " found.")
return(pr)
}
############################################################
## massifquant
##
#' @title Core API function for massifquant peak detection
#'
#' @description Massifquant is a Kalman filter (KF)-based chromatographic peak
#' detection for XC-MS data in centroid mode. The identified peaks
#' can be further refined with the \emph{centWave} method (see
#' \code{\link{do_findChromPeaks_centWave}} for details on centWave)
#' by specifying \code{withWave = TRUE}.
#'
#' @details This algorithm's performance has been tested rigorously
#' on high resolution LC/{OrbiTrap, TOF}-MS data in centroid mode.
#' Simultaneous kalman filters identify peaks and calculate their
#' area under the curve. The default parameters are set to operate on
#' a complex LC-MS Orbitrap sample. Users will find it useful to do some
#' simple exploratory data analysis to find out where to set a minimum
#' intensity, and identify how many scans an average peak spans. The
#' \code{consecMissedLimit} parameter has yielded good performance on
#' Orbitrap data when set to (\code{2}) and on TOF data it was found best
#' to be at (\code{1}). This may change as the algorithm has yet to be
#' tested on many samples. The \code{criticalValue} parameter is perhaps
#' most dificult to dial in appropriately and visual inspection of peak
#' identification is the best suggested tool for quick optimization.
#' The \code{ppm} and \code{checkBack} parameters have shown less influence
#' than the other parameters and exist to give users flexibility and
#' better accuracy.
#'
#' @inheritParams do_findChromPeaks_centWave
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @inheritParams findChromPeaks-massifquant
#'
#' @return
#' A matrix, each row representing an identified chromatographic peak,
#' with columns:
#' \describe{
#' \item{mz}{Intensity weighted mean of m/z values of the peaks across
#' scans.}
#' \item{mzmin}{Minumum m/z of the peak.}
#' \item{mzmax}{Maximum m/z of the peak.}
#' \item{rtmin}{Minimum retention time of the peak.}
#' \item{rtmax}{Maximum retention time of the peak.}
#' \item{rt}{Retention time of the peak's midpoint.}
#' \item{into}{Integrated (original) intensity of the peak.}
#' \item{maxo}{Maximum intensity of the peak.}
#' }
#'
#' If \code{withWave} is set to \code{TRUE}, the result is the same as
#' returned by the \code{\link{do_findChromPeaks_centWave}} method.
#'
#' @family core peak detection functions
#'
#' @seealso \code{\link{massifquant}} for the standard user interface method.
#'
#' @references
#' Conley CJ, Smith R, Torgrip RJ, Taylor RM, Tautenhahn R and Prince JT
#' "Massifquant: open-source Kalman filter-based XC-MS isotope trace feature
#' detection" \emph{Bioinformatics} 2014, 30(18):2636-43.
#'
#' @author Christopher Conley
#'
#' @examples
#'
#' ## Load the test file
#' data(faahko_sub)
#' ## Update the path to the files for the local system
#' dirname(faahko_sub) <- system.file("cdf/KO", package = "faahKO")
#'
#' ## Subset to one file and restrict to a certain retention time range
#' data <- filterRt(filterFile(faahko_sub, 1), c(2500, 3000))
#'
#' ## Get m/z and intensity values
#' mzs <- mz(data)
#' ints <- intensity(data)
#'
#' ## Define the values per spectrum:
#' valsPerSpect <- lengths(mzs)
#'
#' ## Perform the peak detection using massifquant - setting prefilter to
#' ## a high value to speed up the call for the example
#' res <- do_findChromPeaks_massifquant(mz = unlist(mzs), int = unlist(ints),
#' scantime = rtime(data), valsPerSpect = valsPerSpect,
#' prefilter = c(3, 10000))
#' head(res)
do_findChromPeaks_massifquant <- function(mz,
int,
scantime,
valsPerSpect,
ppm = 10,
peakwidth = c(20, 50),
snthresh = 10,
prefilter = c(3, 100),
mzCenterFun = "wMean",
integrate = 1,
mzdiff = -0.001,
fitgauss = FALSE,
noise = 0,
verboseColumns = FALSE,
criticalValue = 1.125,
consecMissedLimit = 2,
unions = 1,
checkBack = 0,
withWave = FALSE) {
message("\n Massifquant, Copyright (C) 2013 Brigham Young University.")
message(" Massifquant comes with ABSOLUTELY NO WARRANTY.",
" See LICENSE for details.", sep ="")
## flush.console()
## TODO @jo Ensure in upstream method that data is in centroided mode!
## TODO @jo Ensure the upstream method did eventual sub-setting on scanrange
## Input argument checking.
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if ((length(mz) != length(int)) | (length(valsPerSpect) != length(scantime))
| (length(mz) != sum(valsPerSpect)))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
if (!is.double(mz))
mz <- as.double(mz)
if (!is.double(int))
int <- as.double(int)
## Fix the mzCenterFun
mzCenterFun <- paste("mzCenter",
gsub(mzCenterFun, pattern = "mzCenter.",
replacement = "", fixed = TRUE), sep=".")
if (!exists(mzCenterFun, mode="function"))
stop("Error: >", mzCenterFun, "< not defined !")
message("\n Detecting mass traces at ",ppm,"ppm ... ", appendLF = FALSE)
flush.console()
massifquantROIs <- do_findKalmanROI(mz = mz, int = int, scantime = scantime,
valsPerSpect = valsPerSpect,
minIntensity = prefilter[2],
minCentroids = peakwidth[1],
criticalVal = criticalValue,
consecMissedLim = consecMissedLimit,
segs = unions, scanBack = checkBack,
ppm = ppm)
message("OK")
if (withWave) {
featlist <- do_findChromPeaks_centWave(mz = mz, int = int,
scantime = scantime,
valsPerSpect = valsPerSpect,
ppm = ppm, peakwidth = peakwidth,
snthresh = snthresh,
prefilter = prefilter,
mzCenterFun = mzCenterFun,
integrate = integrate,
mzdiff = mzdiff,
fitgauss = fitgauss,
noise = noise,
verboseColumns = verboseColumns,
roiList = massifquantROIs)
}
else {
## Get index vector for C calls
scanindex <- valueCount2ScanIndex(valsPerSpect)
basenames <- c("mz","mzmin","mzmax","rtmin","rtmax","rt", "into")
if (length(massifquantROIs) == 0) {
warning("\nNo peaks found!")
nopeaks <- matrix(nrow=0, ncol=length(basenames))
colnames(nopeaks) <- basenames
return(nopeaks)
}
## Get the max intensity for each peak.
maxo <- lapply(massifquantROIs, function(z) {
raw <- .rawMat(mz = mz, int = int, scantime = scantime,
valsPerSpect = valsPerSpect,
mzrange = c(z$mzmin, z$mzmax),
scanrange = c(z$scmin, z$scmax))
max(raw[, 3])
})
## p <- t(sapply(massifquantROIs, unlist))
p <- do.call(rbind, lapply(massifquantROIs, unlist, use.names = FALSE))
colnames(p) <- basenames
p <- cbind(p, maxo = unlist(maxo))
#calculate median index
p[, "rt"] <- as.integer(p[, "rtmin"] + ( (p[, "rt"] + 1) / 2 ) - 1)
#convert from index into actual time
p[, "rtmin"] <- scantime[p[, "rtmin"]]
p[, "rtmax"] <- scantime[p[, "rtmax"]]
p[, "rt"] <- scantime[p[, "rt"]]
uorder <- order(p[, "into"], decreasing = TRUE)
pm <- as.matrix(p[, c("mzmin", "mzmax", "rtmin", "rtmax"),
drop = FALSE])
uindex <- rectUnique(pm, uorder, mzdiff, ydiff = -0.00001) ## allow adjacent peaks;
featlist <- p[uindex, , drop = FALSE]
message(" ", dim(featlist)[1]," Peaks.");
return(featlist)
}
return(featlist)
}
## The version of matchedFilter:
## .matchedFilter_orig: original code, iterative buffer creation.
## .matchedFilter_binYonX_iter: iterative buffer creation but using our binning function.
## .matchedFilter_no_iter: original binning, but a single binning call.
## .matchedFilter_binYonX_no_iter: single binning call using our binning function.
############################################################
## matchedFilter
##
## That's the function that matches the code from the
## findPeaks.matchedFilter method from the xcms package.
## The peak detection is performed on the binned data. Depending on the variable
## `bufsize` the function iteratively bins the intensity values on m/z dimension into
## bins of size `step` always binning into `bufsize` bins. While ensuring low memory
## usage, this iterative buffering is actually quite time consuming.
## The loop runs over the variable `mass` which corresponds to the midpoints of the
## bins. Peak detection is performed for bin `i` considering also `steps` neighboring
## bins. As detailed above, if the index i is outside of the buffer size, the binnin
## is performed for the next chunk of `bufsize` bins.
##
## This function takes basic R-objects and might thus be used as the base analysis
## method for a future xcms API.
## mz is a numeric vector with all m/z values.
## int is a numeric vector with the intensities.
## valsPerSpect: is an integer vector with the number of values per spectrum.
## This will be converted to what xcms calls the scanindex.
## TODO: in the long run it would be better to avoid buffer creation, extending,
## filling and all this stuff being done in a for loop.
## impute: none (=bin), binlin, binlinbase, intlin
## baseValue default: min(int)/2 (smallest value in the whole data set).
##
#' @title Core API function for matchedFilter peak detection
#'
#' @description This function identifies peaks in the chromatographic
#' time domain as described in [Smith 2006]. The intensity values are
#' binned by cutting The LC/MS data into slices (bins) of a mass unit
#' (\code{binSize} m/z) wide. Within each bin the maximal intensity is
#' selected. The peak detection is then performed in each bin by
#' extending it based on the \code{steps} parameter to generate slices
#' comprising bins \code{current_bin - steps +1} to
#' \code{current_bin + steps - 1}.
#' Each of these slices is then filtered with matched filtration using
#' a second-derative Gaussian as the model peak shape. After filtration
#' peaks are detected using a signal-to-ration cut-off. For more details
#' and illustrations see [Smith 2006].
#'
#' @details The intensities are binned by the provided m/z values within each
#' spectrum (scan). Binning is performed such that the bins are centered
#' around the m/z values (i.e. the first bin includes all m/z values between
#' \code{min(mz) - bin_size/2} and \code{min(mz) + bin_size/2}).
#'
#' For more details on binning and missing value imputation see
#' \code{\link{binYonX}} and \code{\link{imputeLinInterpol}} methods.
#'
#' @note This function exposes core peak detection functionality of
#' the \emph{matchedFilter} method. While this function can be called
#' directly, users will generally call the corresponding method for the
#' data object instead (e.g. the \code{link{findPeaks.matchedFilter}}
#' method).
#'
#' @inheritParams do_findChromPeaks_centWave
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @inheritParams imputeLinInterpol
#'
#' @inheritParams findChromPeaks-matchedFilter
#'
#' @return A matrix, each row representing an identified chromatographic peak,
#' with columns:
#' \describe{
#' \item{mz}{Intensity weighted mean of m/z values of the peak across scans.}
#' \item{mzmin}{Minimum m/z of the peak.}
#' \item{mzmax}{Maximum m/z of the peak.}
#' \item{rt}{Retention time of the peak's midpoint.}
#' \item{rtmin}{Minimum retention time of the peak.}
#' \item{rtmax}{Maximum retention time of the peak.}
#' \item{into}{Integrated (original) intensity of the peak.}
#' \item{intf}{Integrated intensity of the filtered peak.}
#' \item{maxo}{Maximum intensity of the peak.}
#' \item{maxf}{Maximum intensity of the filtered peak.}
#' \item{i}{Rank of peak in merged EIC (\code{<= max}).}
#' \item{sn}{Signal to noise ratio of the peak}
#' }
#'
#' @references
#' Colin A. Smith, Elizabeth J. Want, Grace O'Maille, Ruben Abagyan and
#' Gary Siuzdak. "XCMS: Processing Mass Spectrometry Data for Metabolite
#' Profiling Using Nonlinear Peak Alignment, Matching, and Identification"
#' \emph{Anal. Chem.} 2006, 78:779-787.
#'
#' @author Colin A Smith, Johannes Rainer
#'
#' @family core peak detection functions
#'
#' @seealso \code{\link{binYonX}} for a binning function,
#' \code{\link{imputeLinInterpol}} for the interpolation of missing values.
#' \code{\link{matchedFilter}} for the standard user interface method.
#'
#' @examples
#'
#' ## Load the test file
#' data(faahko_sub)
#' ## Update the path to the files for the local system
#' dirname(faahko_sub) <- system.file("cdf/KO", package = "faahKO")
#'
#' ## Subset to one file and restrict to a certain retention time range
#' data <- filterRt(filterFile(faahko_sub, 1), c(2500, 3000))
#'
#' ## Get m/z and intensity values
#' mzs <- mz(data)
#' ints <- intensity(data)
#'
#' ## Define the values per spectrum:
#' valsPerSpect <- lengths(mzs)
#'
#' res <- do_findChromPeaks_matchedFilter(mz = unlist(mzs), int = unlist(ints),
#' scantime = rtime(data), valsPerSpect = valsPerSpect)
#' head(res)
do_findChromPeaks_matchedFilter <- function(mz,
int,
scantime,
valsPerSpect,
binSize = 0.1,
impute = "none",
baseValue,
distance,
fwhm = 30,
sigma = fwhm/2.3548,
max = 5,
snthresh = 10,
steps = 2,
mzdiff = 0.8 - binSize * steps,
index = FALSE,
sleep = 0
){
## Use original code
if (useOriginalCode()) {
return(.matchedFilter_orig(mz, int, scantime, valsPerSpect,
binSize, impute, baseValue, distance,
fwhm, sigma, max, snthresh,
steps, mzdiff, index, sleep = sleep))
} else {
return(.matchedFilter_binYonX_no_iter(mz, int, scantime, valsPerSpect,
binSize, impute, baseValue,
distance, fwhm, sigma, max,
snthresh, steps, mzdiff, index,
sleep = sleep
))
}
}
.matchedFilter_orig <- function(mz,
int,
scantime,
valsPerSpect,
binSize = 0.1,
impute = "none",
baseValue,
distance,
fwhm = 30,
sigma = fwhm/2.3548,
max = 5,
snthresh = 10,
steps = 2,
mzdiff = 0.8 - binSize * steps,
index = FALSE,
sleep = 0
){
.Deprecated(msg = paste0("Use of the original code with iterative binning",
" is discouraged!"))
## Map arguments to findPeaks.matchedFilter arguments.
step <- binSize
profMeths <- c("profBinM", "profBinLinM", "profBinLinBaseM", "profIntLinM")
names(profMeths) <- c("none", "lin", "linbase", "intlin")
impute <- match.arg(impute, names(profMeths))
profFun <- profMeths[impute]
profFun <- match.fun(profFun)
## Input argument checking.
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if (length(mz) != length(int) | length(valsPerSpect) != length(scantime)
| length(mz) != sum(valsPerSpect))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
## Calculate a the "scanindex" from the number of values per spectrum:
scanindex <- valueCount2ScanIndex(valsPerSpect)
## Create EIC buffer
mrange <- range(mz)
## Create a numeric vector of masses; these will be the mid-points of the bins.
mass <- seq(floor(mrange[1]/step)*step, ceiling(mrange[2]/step)*step, by = step)
## Calculate the /real/ bin size (as in xcms.c code).
bin_size <- (max(mass) - min(mass)) / (length(mass) - 1)
bufsize_base <- 100
bufsize <- min(bufsize_base, length(mass))
## Define profparam:
profp <- list()
if (missing(baseValue))
baseValue <- numeric()
if (length(baseValue) == 0)
baseValue <- min(int, na.rm = TRUE) / 2
profp$baselevel <- baseValue
if (missing(distance))
distance <- numeric()
if (length(distance) != 0) {
profp$basespace <- distance * bin_size
} else {
profp$basespace <- 0.075
distance <- floor(0.075 / bin_size)
}
## This returns a matrix, ncol equals the number of spectra, nrow the bufsize.
## ? named args?
buf <- profFun(x = mz, y = int, zidx = scanindex, num = bufsize,
xstart = mass[1], xend = mass[bufsize], NAOK = TRUE,
param = profp)
bufMax <- profMaxIdxM(mz, int, scanindex, bufsize, mass[1], mass[bufsize],
TRUE, profp)
bufidx <- integer(length(mass))
idxrange <- c(1, bufsize)
bufidx[idxrange[1]:idxrange[2]] <- 1:bufsize
lookahead <- steps-1
lookbehind <- 1 ## always 1?
N <- nextn(length(scantime))
xrange <- range(scantime)
x <- c(0:(N/2), -(ceiling(N/2-1)):-1)*(xrange[2]-xrange[1])/(length(scantime)-1)
filt <- -attr(eval(deriv3(~ 1/(sigma*sqrt(2*pi))*exp(-x^2/(2*sigma^2)), "x")), "hessian")
filt <- filt/sqrt(sum(filt^2))
filt <- fft(filt, inverse = TRUE)/length(filt)
cnames <- c("mz", "mzmin", "mzmax", "rt", "rtmin", "rtmax", "into", "intf",
"maxo", "maxf", "i", "sn")
rmat <- matrix(nrow = 2048, ncol = length(cnames))
num <- 0
for (i in seq(length = (length(mass)-steps+1))) {
## Update EIC buffer if necessary
if (bufidx[i+lookahead] == 0) {
bufidx[idxrange[1]:idxrange[2]] <- 0
idxrange <- c(max(1, i - lookbehind), min(bufsize+i-1-lookbehind,
length(mass)))
bufidx[idxrange[1]:idxrange[2]] <- 1:(diff(idxrange)+1)
buf <- profFun(x = mz, y = int, zidx = scanindex,
num = diff(idxrange) + 1, xstart = mass[idxrange[1]],
xend = mass[idxrange[2]], NAOK = TRUE,
param = profp)
bufMax <- profMaxIdxM(mz, int, scanindex, diff(idxrange)+1,
mass[idxrange[1]],
mass[idxrange[2]], TRUE, profp)
}
ymat <- buf[bufidx[i:(i+steps-1)],,drop=FALSE]
ysums <- colMax(ymat)
yfilt <- filtfft(ysums, filt)
gmax <- max(yfilt)
## Just look for 'max' number of peaks within the bin/slice.
for (j in seq(length = max)) {
maxy <- which.max(yfilt)
noise <- mean(ysums[ysums > 0])
##noise <- mean(yfilt[yfilt >= 0])
sn <- yfilt[maxy]/noise
if (yfilt[maxy] > 0 && yfilt[maxy] > snthresh*noise && ysums[maxy] > 0) {
peakrange <- descendZero(yfilt, maxy)
intmat <- ymat[, peakrange[1]:peakrange[2], drop = FALSE]
mzmat <- matrix(mz[bufMax[bufidx[i:(i+steps-1)],
peakrange[1]:peakrange[2]]],
nrow = steps)
which.intMax <- which.colMax(intmat)
mzmat <- mzmat[which.intMax]
if (all(is.na(mzmat))) {
yfilt[peakrange[1]:peakrange[2]] <- 0
next
}
mzrange <- range(mzmat, na.rm = TRUE)
massmean <- weighted.mean(mzmat, intmat[which.intMax], na.rm = TRUE)
## This case (the only non-na m/z had intensity 0) was reported
## by Gregory Alan Barding "binlin processing"
if(any(is.na(massmean))) {
massmean <- mean(mzmat, na.rm = TRUE)
}
pwid <- (scantime[peakrange[2]] - scantime[peakrange[1]]) /
(peakrange[2] - peakrange[1])
into <- pwid*sum(ysums[peakrange[1]:peakrange[2]])
intf <- pwid*sum(yfilt[peakrange[1]:peakrange[2]])
maxo <- max(ysums[peakrange[1]:peakrange[2]])
maxf <- yfilt[maxy]
## -- begin sleep/plot
if (sleep > 0) {
plot(scantime, yfilt, type = "l",
main = paste(mass[i], "-", mass[i+1]),
ylim = c(-gmax/3, gmax))
points(cbind(scantime, yfilt)[peakrange[1]:peakrange[2],],
type = "l", col = "red")
points(scantime, colSums(ymat), type = "l", col = "blue",
lty = "dashed")
abline(h = snthresh*noise, col = "red")
Sys.sleep(sleep)
}
## -- end sleep plot
yfilt[peakrange[1]:peakrange[2]] <- 0
num <- num + 1
## Double the size of the output matrix if it's full
if (num > nrow(rmat)) {
nrmat <- matrix(nrow = 2*nrow(rmat), ncol = ncol(rmat))
nrmat[seq(length = nrow(rmat)),] = rmat
rmat <- nrmat
}
rmat[num,] <- c(massmean, mzrange[1], mzrange[2], maxy, peakrange,
into, intf, maxo, maxf, j, sn)
} else
break
}
}
colnames(rmat) <- cnames
rmat <- rmat[seq(length = num),]
max <- max-1 + max*(steps-1) + max*ceiling(mzdiff/step)
if (index)
mzdiff <- mzdiff/step
else {
rmat[,"rt"] <- scantime[rmat[,"rt"]]
rmat[,"rtmin"] <- scantime[rmat[,"rtmin"]]
rmat[,"rtmax"] <- scantime[rmat[,"rtmax"]]
}
## Select for each unique mzmin, mzmax, rtmin, rtmax the largest peak
## and report that.
uorder <- order(rmat[,"into"], decreasing=TRUE)
uindex <- rectUnique(rmat[,c("mzmin","mzmax","rtmin","rtmax"),drop=FALSE],
uorder, mzdiff)
rmat <- rmat[uindex,,drop=FALSE]
return(rmat)
}
############################################################
## The code of this function is basically the same than of the original
## findPeaks.matchedFilter method in xcms with the following differences:
## o Create the full 'profile matrix' (i.e. the m/z binned matrix) once
## instead of repeatedly creating a "buffer" of 100 m/z values.
## o Append the identified peaks to a list instead of generating a matrix
## with a fixed set of rows which is doubled in its size each time more
## peaks are identified than there are rows in the matrix.
## o Use binYonX and imputeLinInterpol instead of the profBin... methods.
.matchedFilter_binYonX_no_iter <- function(mz,
int,
scantime,
valsPerSpect,
binSize = 0.1,
impute = "none",
baseValue,
distance,
fwhm = 30,
sigma = fwhm/2.3548,
max = 5,
snthresh = 10,
steps = 2,
mzdiff = 0.8 - binSize * steps,
index = FALSE,
sleep = 0
){
## Input argument checking.
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if (length(mz) != length(int) | length(valsPerSpect) != length(scantime)
| length(mz) != sum(valsPerSpect))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
## Generate the 'profile' matrix, i.e. perform the binning:
mrange <- range(mz[mz > 0])
mass <- seq(floor(mrange[1] / binSize) * binSize,
ceiling(mrange[2] / binSize) * binSize,
by = binSize)
## Get the imputation method: allowed: none, lin, linbase and intlin
impute <- match.arg(impute, c("none", "lin", "linbase", "intlin"))
## Select the profFun and the settings for it...
if (impute == "intlin") {
## intlin not yet implemented...
profFun = "profIntLinM"
profp <- list()
## Calculate the "scanindex" from the number of values per spectrum:
scanindex <- valueCount2ScanIndex(valsPerSpect)
bufsize <- length(mass)
buf <- do.call(profFun, args = list(mz, int, scanindex, bufsize,
mass[1], mass[bufsize],
TRUE))
## The full matrix, nrow is the total number of (binned) m/z values.
bufMax <- profMaxIdxM(mz, int, scanindex, bufsize, mass[1],
mass[bufsize], TRUE, profp)
} else {
## Binning the data.
## Create and translate settings for binYonX
toIdx <- cumsum(valsPerSpect)
fromIdx <- c(1L, toIdx[-length(toIdx)] + 1L)
shiftBy = TRUE
binFromX <- min(mass)
binToX <- max(mass)
## binSize <- (binToX - binFromX) / (length(mass) - 1)
## brks <- seq(binFromX - binSize/2, binToX + binSize/2, by = binSize)
brks <- breaks_on_nBins(fromX = binFromX, toX = binToX,
nBins = length(mass), shiftByHalfBinSize = TRUE)
binRes <- binYonX(mz, int,
breaks = brks,
fromIdx = fromIdx,
toIdx = toIdx,
baseValue = ifelse(impute == "none", yes = 0, no = NA),
sortedX = TRUE,
returnIndex = TRUE
)
if (length(toIdx) == 1)
binRes <- list(binRes)
bufMax <- do.call(cbind, lapply(binRes, function(z) return(z$index)))
bin_size <- binRes[[1]]$x[2] - binRes[[1]]$x[1]
## Missing value imputation
if (missing(baseValue))
baseValue <- numeric()
if (length(baseValue) == 0)
baseValue <- min(int, na.rm = TRUE) / 2
if (missing(distance))
distance <- numeric()
if (length(distance) == 0)
distance <- floor(0.075 / bin_size)
binVals <- lapply(binRes, function(z) {
return(imputeLinInterpol(z$y, method = impute, distance = distance,
noInterpolAtEnds = TRUE,
baseValue = baseValue))
})
buf <- do.call(cbind, binVals)
}
bufidx <- 1L:length(mass)
lookahead <- steps-1
lookbehind <- 1
N <- nextn(length(scantime))
xrange <- range(scantime)
x <- c(0:(N/2), -(ceiling(N/2-1)):-1) *
(xrange[2]-xrange[1])/(length(scantime)-1)
filt <- -attr(eval(deriv3(~ 1/(sigma*sqrt(2*pi)) *
exp(-x^2/(2*sigma^2)), "x")), "hessian")
filt <- filt/sqrt(sum(filt^2))
filt <- fft(filt, inverse = TRUE)/length(filt)
cnames <- c("mz", "mzmin", "mzmax", "rt", "rtmin", "rtmax", "into", "intf",
"maxo", "maxf", "i", "sn")
num <- 0
ResList <- list()
## Can not do much here, lapply/apply won't work because of the 'steps' parameter.
## That's looping through the masses, i.e. rows of the profile matrix.
for (i in seq(length = length(mass)-steps+1)) {
ymat <- buf[bufidx[i:(i+steps-1)], , drop = FALSE]
ysums <- colMax(ymat)
yfilt <- filtfft(ysums, filt)
gmax <- max(yfilt)
for (j in seq(length = max)) {
maxy <- which.max(yfilt)
noise <- mean(ysums[ysums > 0])
##noise <- mean(yfilt[yfilt >= 0])
sn <- yfilt[maxy]/noise
if (yfilt[maxy] > 0 && yfilt[maxy] > snthresh*noise && ysums[maxy] > 0) {
peakrange <- descendZero(yfilt, maxy)
intmat <- ymat[, peakrange[1]:peakrange[2], drop = FALSE]
mzmat <- matrix(mz[bufMax[bufidx[i:(i+steps-1)],
peakrange[1]:peakrange[2]]],
nrow = steps)
which.intMax <- which.colMax(intmat)
mzmat <- mzmat[which.intMax]
if (all(is.na(mzmat))) {
yfilt[peakrange[1]:peakrange[2]] <- 0
next
}
mzrange <- range(mzmat, na.rm = TRUE)
massmean <- weighted.mean(mzmat, intmat[which.intMax],
na.rm = TRUE)
## This case (the only non-na m/z had intensity 0) was reported
## by Gregory Alan Barding "binlin processing"
if(any(is.na(massmean))) {
massmean <- mean(mzmat, na.rm = TRUE)
}
pwid <- (scantime[peakrange[2]] - scantime[peakrange[1]]) /
(peakrange[2] - peakrange[1])
into <- pwid*sum(ysums[peakrange[1]:peakrange[2]])
intf <- pwid*sum(yfilt[peakrange[1]:peakrange[2]])
maxo <- max(ysums[peakrange[1]:peakrange[2]])
maxf <- yfilt[maxy]
## begin sleep/plot
if (sleep > 0) {
plot(scantime, yfilt, type = "l",
main = paste(mass[i], "-", mass[i+1]),
ylim=c(-gmax/3, gmax))
points(cbind(scantime, yfilt)[peakrange[1]:peakrange[2],],
type = "l", col = "red")
points(scantime, colSums(ymat), type = "l", col = "blue",
lty = "dashed")
abline(h = snthresh*noise, col = "red")
Sys.sleep(sleep)
}
## end sleep/plot
yfilt[peakrange[1]:peakrange[2]] <- 0
num <- num + 1
ResList[[num]] <- c(massmean, mzrange[1], mzrange[2], maxy,
peakrange, into, intf, maxo, maxf, j, sn)
} else
break
}
}
if (length(ResList) == 0) {
rmat <- matrix(nrow = 0, ncol = length(cnames))
colnames(rmat) <- cnames
return(rmat)
}
rmat <- do.call(rbind, ResList)
if (is.null(dim(rmat))) {
rmat <- matrix(rmat, nrow = 1)
}
colnames(rmat) <- cnames
max <- max-1 + max*(steps-1) + max*ceiling(mzdiff/binSize)
if (index)
mzdiff <- mzdiff/binSize
else {
rmat[, "rt"] <- scantime[rmat[, "rt"]]
rmat[, "rtmin"] <- scantime[rmat[, "rtmin"]]
rmat[, "rtmax"] <- scantime[rmat[, "rtmax"]]
}
## Select for each unique mzmin, mzmax, rtmin, rtmax the largest peak
## and report that.
uorder <- order(rmat[, "into"], decreasing = TRUE)
uindex <- rectUnique(rmat[, c("mzmin", "mzmax", "rtmin", "rtmax"),
drop = FALSE],
uorder, mzdiff)
rmat <- rmat[uindex,,drop = FALSE]
return(rmat)
}
############################################################
## MSW
##
#' @title Core API function for single-spectrum non-chromatography MS data
#' peak detection
#'
#' @description This function performs peak detection in mass spectrometry
#' direct injection spectrum using a wavelet based algorithm.
#'
#' @details This is a wrapper around the peak picker in Bioconductor's
#' \code{MassSpecWavelet} package calling
#' \code{\link{peakDetectionCWT}} and
#' \code{\link{tuneInPeakInfo}} functions. See the
#' \emph{xcmsDirect} vignette for more information.
#'
#' @inheritParams do_findChromPeaks_centWave
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @param ... Additional parameters to be passed to the
#' \code{\link{peakDetectionCWT}} function.
#'
#' @return A matrix, each row representing an identified peak, with columns:
#' \describe{
#' \item{mz}{m/z value of the peak at the centroid position.}
#' \item{mzmin}{Minimum m/z of the peak.}
#' \item{mzmax}{Maximum m/z of the peak.}
#' \item{rt}{Always \code{-1}.}
#' \item{rtmin}{Always \code{-1}.}
#' \item{rtmax}{Always \code{-1}.}
#' \item{into}{Integrated (original) intensity of the peak.}
#' \item{maxo}{Maximum intensity of the peak.}
#' \item{intf}{Always \code{NA}.}
#' \item{maxf}{Maximum MSW-filter response of the peak.}
#' \item{sn}{Signal to noise ratio.}
#' }
#'
#' @family core peak detection functions
#'
#' @seealso \code{\link{MSW}} for the standard user interface
#' method. \code{\link{peakDetectionCWT}} from the
#' \code{MassSpecWavelet} package.
#'
#' @author Joachim Kutzera, Steffen Neumann, Johannes Rainer
do_findPeaks_MSW <- function(mz, int, snthresh = 3,
verboseColumns = FALSE, ...) {
## Input argument checking.
if (missing(int))
stop("Argument 'int' is missing!")
if (missing(mz))
stop("Argument 'mz' is missing!")
if (length(int) != length(mz))
stop("Length of 'int' and 'mz' do not match!")
if (!is.numeric(int) | !is.numeric(mz))
stop("'int' and 'mz' are supposed to be numeric vectors!")
## MassSpecWavelet Calls
peakInfo <- peakDetectionCWT(int, SNR.Th = snthresh, ...)
majorPeakInfo <- peakInfo$majorPeakInfo
sumIntos <- function(into, inpos, scale){
scale = floor(scale)
sum(into[(inpos-scale):(inpos+scale)])
}
maxIntos <- function(into, inpos, scale){
scale = floor(scale)
max(into[(inpos-scale):(inpos+scale)])
}
betterPeakInfo <- tuneInPeakInfo(int,
majorPeakInfo)
peakIndex <- betterPeakInfo$peakIndex
nPeaks <- length(peakIndex)
## sum and max of raw values, sum and max of filter-response
rints <- numeric(nPeaks)
fints <- NA
maxRints <- numeric(nPeaks)
maxFints <- NA
for (a in 1:nPeaks) {
rints[a] <- sumIntos(int, peakIndex[a],
betterPeakInfo$peakScale[a])
maxRints[a] <- maxIntos(int, peakIndex[a],
betterPeakInfo$peakScale[a])
}
## filter-response is not summed here, the maxF-value is the one
## which was "xcmsRaw$into" earlier
## Assemble result
basenames <- c("mz","mzmin","mzmax","rt","rtmin","rtmax",
"into","maxo","sn","intf","maxf")
peaklist <- matrix(-1, nrow = nPeaks, ncol = length(basenames))
colnames(peaklist) <- c(basenames)
peaklist[,"mz"] <- mz[peakIndex]
peaklist[,"mzmin"] <- mz[(peakIndex - betterPeakInfo$peakScale)]
peaklist[,"mzmax"] <- mz[(peakIndex + betterPeakInfo$peakScale)]
## peaklist[,"rt"] <- rep(-1, length(peakIndex))
## peaklist[,"rtmin"] <- rep(-1, length(peakIndex))
## peaklist[,"rtmax"] <- rep(-1, length(peakIndex))
peaklist[,"into"] <- rints ## sum of raw-intensities
peaklist[,"maxo"] <- maxRints
peaklist[,"intf"] <- rep(NA, nPeaks)
peaklist[,"maxf"] <- betterPeakInfo$peakValue
peaklist[,"sn"] <- betterPeakInfo$peakSNR
## cat('\n')
## Filter additional (verbose) columns
if (!verboseColumns)
peaklist <- peaklist[,basenames,drop=FALSE]
peaklist
}
############################################################
## The original code
## This should be removed at some point.
.MSW_orig <- function(mz, int, snthresh = 3, verboseColumns = FALSE, ...) {
## MassSpecWavelet Calls
peakInfo <- peakDetectionCWT(int, SNR.Th=snthresh, ...)
majorPeakInfo <- peakInfo$majorPeakInfo
sumIntos <- function(into, inpos, scale){
scale=floor(scale)
sum(into[(inpos-scale):(inpos+scale)])
}
maxIntos <- function(into, inpos, scale){
scale=floor(scale)
max(into[(inpos-scale):(inpos+scale)])
}
betterPeakInfo <- tuneInPeakInfo(int,
majorPeakInfo)
peakIndex <- betterPeakInfo$peakIndex
## sum and max of raw values, sum and max of filter-response
rints<-NA;fints<-NA
maxRints<-NA;maxFints<-NA
for (a in 1:length(peakIndex)) {
rints[a] <- sumIntos(int,peakIndex[a],
betterPeakInfo$peakScale[a])
maxRints[a] <- maxIntos(int,peakIndex[a],
betterPeakInfo$peakScale[a])
}
## filter-response is not summed here, the maxF-value is the one
## which was "xcmsRaw$into" earlier
## Assemble result
basenames <- c("mz","mzmin","mzmax","rt","rtmin","rtmax",
"into","maxo","sn","intf","maxf")
peaklist <- matrix(-1, nrow = length(peakIndex), ncol = length(basenames))
colnames(peaklist) <- c(basenames)
peaklist[,"mz"] <- mz[peakIndex]
peaklist[,"mzmin"] <- mz[(peakIndex-betterPeakInfo$peakScale)]
peaklist[,"mzmax"] <- mz[(peakIndex+betterPeakInfo$peakScale)]
peaklist[,"rt"] <- rep(-1, length(peakIndex))
peaklist[,"rtmin"] <- rep(-1, length(peakIndex))
peaklist[,"rtmax"] <- rep(-1, length(peakIndex))
peaklist[,"into"] <- rints ## sum of raw-intensities
peaklist[,"maxo"] <- maxRints
peaklist[,"intf"] <- rep(NA, length(peakIndex))
peaklist[,"maxf"] <- betterPeakInfo$peakValue
peaklist[,"sn"] <- betterPeakInfo$peakSNR
cat('\n')
## Filter additional (verbose) columns
if (!verboseColumns)
peaklist <- peaklist[,basenames,drop=FALSE]
peaklist
}
############################################################
## The original code
## This should be removed at some point.
.MSW_orig <- function(mz, int, snthresh = 3, verboseColumns = FALSE, ...) {
## MassSpecWavelet Calls
peakInfo <- peakDetectionCWT(int, SNR.Th=snthresh, ...)
majorPeakInfo <- peakInfo$majorPeakInfo
sumIntos <- function(into, inpos, scale){
scale=floor(scale)
sum(into[(inpos-scale):(inpos+scale)])
}
maxIntos <- function(into, inpos, scale){
scale=floor(scale)
max(into[(inpos-scale):(inpos+scale)])
}
betterPeakInfo <- tuneInPeakInfo(int,
majorPeakInfo)
peakIndex <- betterPeakInfo$peakIndex
## sum and max of raw values, sum and max of filter-response
rints<-NA;fints<-NA
maxRints<-NA;maxFints<-NA
for (a in 1:length(peakIndex)) {
rints[a] <- sumIntos(int,peakIndex[a],
betterPeakInfo$peakScale[a])
maxRints[a] <- maxIntos(int,peakIndex[a],
betterPeakInfo$peakScale[a])
}
## filter-response is not summed here, the maxF-value is the one
## which was "xcmsRaw$into" earlier
## Assemble result
basenames <- c("mz","mzmin","mzmax","rt","rtmin","rtmax",
"into","maxo","sn","intf","maxf")
peaklist <- matrix(-1, nrow = length(peakIndex), ncol = length(basenames))
colnames(peaklist) <- c(basenames)
peaklist[,"mz"] <- mz[peakIndex]
peaklist[,"mzmin"] <- mz[(peakIndex-betterPeakInfo$peakScale)]
peaklist[,"mzmax"] <- mz[(peakIndex+betterPeakInfo$peakScale)]
peaklist[,"rt"] <- rep(-1, length(peakIndex))
peaklist[,"rtmin"] <- rep(-1, length(peakIndex))
peaklist[,"rtmax"] <- rep(-1, length(peakIndex))
peaklist[,"into"] <- rints ## sum of raw-intensities
peaklist[,"maxo"] <- maxRints
peaklist[,"intf"] <- rep(NA, length(peakIndex))
peaklist[,"maxf"] <- betterPeakInfo$peakValue
peaklist[,"sn"] <- betterPeakInfo$peakSNR
cat('\n')
## Filter additional (verbose) columns
if (!verboseColumns)
peaklist <- peaklist[,basenames,drop=FALSE]
peaklist
}
############################################################
## MS1
## This one might be too cumbersome to do it for plain vectors. It would be ideal
## for MSnExp objects though.
##
## do_findChromPeaks_MS1 <- function(mz, int, scantime, valsPerSpect) {
## ## Checks: do I have
## }
## ## Original code: TODO REMOVE ME once method is validated.
## do_predictIsotopeROIs <- function(object,
## xcmsPeaks, ppm=25,
## maxcharge=3, maxiso=5, mzIntervalExtension=TRUE) {
## if(nrow(xcmsPeaks) == 0){
## warning("Warning: There are no peaks (parameter >xcmsPeaks<) for the prediction of isotope ROIs !\n")
## return(list())
## }
## if(class(xcmsPeaks) != "xcmsPeaks")
## stop("Error: parameter >xcmsPeaks< is not of class 'xcmsPeaks' ! \n")
## if(any(is.na(match(x = c("scmin", "scmax"), table = colnames(xcmsPeaks)))))
## stop("Error: peak list >xcmsPeaks< is missing the columns 'scmin' and 'scmax' ! Please set parameter >verbose.columns< to TRUE for peak picking with 'centWave' and try again ! \n")
## addNewIsotopeROIs <- TRUE
## addNewAdductROIs <- FALSE
## polarity <- NA
## ## convert present peaks to list of lists
## presentROIs.list <- list()
## for(peakIdx in 1:nrow(xcmsPeaks)){
## presentROIs.list[[peakIdx]] <- list(
## mz = xcmsPeaks[[peakIdx, "mz"]],## XXX not used!
## mzmin = xcmsPeaks[[peakIdx, "mzmin"]],
## mzmax = xcmsPeaks[[peakIdx, "mzmax"]],
## scmin = xcmsPeaks[[peakIdx, "scmin"]],
## scmax = xcmsPeaks[[peakIdx, "scmax"]],
## length = -1,## XXX not used!
## intensity = xcmsPeaks[[peakIdx, "intb"]],## XXX not used!
## scale = xcmsPeaks[[peakIdx, "scale"]]## XXX not used!
## )
## if(abs(xcmsPeaks[[peakIdx, "mzmax"]] - xcmsPeaks[[peakIdx, "mzmin"]]) < xcmsPeaks[[peakIdx, "mz"]] * ppm / 1E6){
## presentROIs.list[[peakIdx]]$mzmin <- xcmsPeaks[[peakIdx, "mz"]] - xcmsPeaks[[peakIdx, "mz"]] * (ppm/2) / 1E6
## presentROIs.list[[peakIdx]]$mzmax <- xcmsPeaks[[peakIdx, "mz"]] + xcmsPeaks[[peakIdx, "mz"]] * (ppm/2) / 1E6
## }
## }
## ## fetch predicted ROIs
## resultObj <- createAdditionalROIs(object, presentROIs.list, ppm, addNewIsotopeROIs, maxcharge, maxiso, mzIntervalExtension, addNewAdductROIs, polarity)
## newRoiCounter <- resultObj$newRoiCounter
## numberOfAdditionalIsotopeROIs <- resultObj$numberOfAdditionalIsotopeROIs
## numberOfAdditionalAdductROIs <- resultObj$numberOfAdditionalAdductROIs
## newROI.matrix <- resultObj$newROI.matrix
## if(nrow(newROI.matrix) == 0)
## return(list())
## ## This should not be needed, as it has already been performed above.
## ## remove ROIs with weak signal content
## intensityThreshold <- 10
## newROI.matrix <- removeROIsWithoutSignal(object, newROI.matrix, intensityThreshold)
## ## convert to list of lists
## newROI.list <- list()
## for(idx in 1:nrow(newROI.matrix))
## ## c("mz", "mzmin", "mzmax", "scmin", "scmax", "length", "intensity")
## newROI.list[[length(newROI.list) + 1]] <- as.list(newROI.matrix[idx, ])
## cat("Predicted ROIs: ", length(newROI.list), " new ROIs (", numberOfAdditionalIsotopeROIs, " isotope ROIs, ", numberOfAdditionalAdductROIs, " adduct ROIs) for ", length(presentROIs.list)," present ROIs.", "\n")
## return(newROI.list)
## }
## Tuned from the original code.
#' @param peaks. \code{matrix} or \code{data.frame} with peaks for which
#' isotopes should be predicted. Required columns are \code{"mz"},
#' \code{"mzmin"}, \code{"mzmax"}, \code{"scmin"}, \code{"scmax"},
#' \code{"intb"} and \code{"scale"}.
#'
#' @return a \code{matrix} with columns \code{"mz"}, \code{"mzmin"},
#' \code{"mzmax"}, \code{"scmin"}, \code{"scmax"}, \code{"length"} (always -1),
#' \code{"intensity"} (always -1) and \code{"scale"}.
#' @noRd
do_define_isotopes <- function(peaks., maxCharge = 3, maxIso = 5,
mzIntervalExtension = TRUE) {
req_cols <- c("mz", "mzmin", "mzmax", "scmin", "scmax", "scale")
if (is.null(dim(peaks.)))
stop("'peaks.' has to be a matrix or data.frame!")
if (!all(req_cols %in% colnames(peaks.))) {
not_there <- req_cols[!(req_cols %in% colnames(peaks.))]
stop("'peaks.' lacks required columns ",
paste0("'", not_there, "'", collapse = ","), "!")
}
if (is.data.frame(peaks.))
peaks. <- as.matrix(peaks.)
isotopeDistance <- 1.0033548378
charges <- 1:maxCharge
isos <- 1:maxIso
isotopePopulationMz <- unique(as.numeric(matrix(isos, ncol = 1) %*%
(isotopeDistance / charges)))
## split the peaks into a list.
roiL <- split(peaks.[, req_cols, drop = FALSE], f = 1:nrow(peaks.))
newRois <- lapply(roiL, function(z) {
if (mzIntervalExtension)
mz_ext <- (z[3] - z[2]) * 2
else
mz_ext <- 0
return(cbind(mz = z[1] + isotopePopulationMz,
mzmin = z[2] + isotopePopulationMz - mz_ext,
mzmax = z[3] + isotopePopulationMz + mz_ext,
scmin = z[4],
scmax = z[5],
length = -1,
intensity = -1,
scale = z[6])
)
})
return(do.call(rbind, newRois))
}
#' @param peaks. see do_define_isotopes
#'
#' @param polarity character(1) defining the polarity, either \code{"positive"}
#' or \code{"negative"}.
#'
#' @note
#'
#' Reference for considered adduct distances:
#' Huang N.; Siegel M.M.1; Kruppa G.H.; Laukien F.H.; J Am Soc Mass Spectrom
#' 1999, 10, 1166-1173.
#'
#' Reference for contaminants:
#' Interferences and comtaminants encountered in modern mass spectrometry
#' Bernd O. Keller, Jie Sui, Alex B. Young and Randy M. Whittal, ANALYTICA
#' CHIMICA ACTA, 627 (1): 71-81)
#'
#' @return see do_define_isotopes.
#'
#' @noRd
do_define_adducts <- function(peaks., polarity = "positive") {
req_cols <- c("mz", "mzmin", "mzmax", "scmin", "scmax", "scale")
if (is.null(dim(peaks.)))
stop("'peaks.' has to be a matrix or data.frame!")
if (!all(req_cols %in% colnames(peaks.))) {
not_there <- req_cols[!(req_cols %in% colnames(peaks.))]
stop("'peaks.' lacks required columns ",
paste0("'", not_there, "'", collapse = ","), "!")
}
if (is.data.frame(peaks.))
peaks. <- as.matrix(peaks.)
mH <- 1.0078250322
mNa <- 22.98976928
mK <- 38.96370649
mC <- 12
mN <- 14.003074004
mO <- 15.994914620
mS <- 31.972071174
mCl <- 34.9688527
mBr <- 78.918338
mF <- 18.998403163
mDMSO <- mC * 2 + mH * 6 + mS + mO # dimethylsulfoxid
mACN <- mC * 2 + mH * 3 + mN # acetonitril
mIsoProp <- mC * 3 + mH * 8 + mO # isopropanol
mNH4 <- mN + mH * 4 # ammonium
mCH3OH <- mC + mH * 3 + mO + mH # methanol
mH2O <- mH * 2 + mO # water
mFA <- mC + mH * 2 + mO * 2 # formic acid
mHAc <- mC + mH * 3 + mC + mO + mO + mH # acetic acid
mTFA <- mC + mF * 3 + mC + mO + mO + mH # trifluoroacetic acid
switch(polarity,
"positive"={
adductPopulationMz <- unlist(c(
## [M+H]+ to [M+H]+ (Reference)
## [M+H]+ to [M+NH4]+
function(mass){ mass - mH + mNH4 },
## [M+H]+ to [M+Na]+
function(mass){ mass - mH + mNa },
## [M+H]+ to [M+CH3OH+H]+
function(mass){ mass + mCH3OH },
## [M+H]+ to [M+K]+
function(mass){ mass - mH + mK },
## [M+H]+ to [M+ACN+H]+
function(mass){ mass + mACN },
## [M+H]+ to [M+2Na-H]+
function(mass){ mass - 2 * mH + 2 * mNa },
## [M+H]+ to [M+IsoProp+H]+
function(mass){ mass + mIsoProp },
## [M+H]+ to [M+ACN+Na]+
function(mass){ mass - mH + mACN + mNa },
## [M+H]+ to [M+2K-H]+
function(mass){ mass - 2 * mH + 2 * mK },
## [M+H]+ to [M+DMSO+H]+
function(mass){ mass + mDMSO },
## [M+H]+ to [M+2*ACN+H]+
function(mass){ mass + 2 * mACN },
## [M+H]+ to [M+IsoProp+Na+H]+ TODO double-charged?
function(mass){ mass + mIsoProp + mNa },
## [M+H]+ to [2M+H]+
function(mass){ (mass - mH) * 2 + mH },
## [M+H]+ to [2M+NH4]+
function(mass){ (mass - mH) * 2 + mNH4 },
## [M+H]+ to [2M+Na]+
function(mass){ (mass - mH) * 2 + mNa },
## [M+H]+ to [2M+K]+
function(mass){ (mass - mH) * 2 + mK },
## [M+H]+ to [2M+ACN+H]+
function(mass){ (mass - mH) * 2 + mACN + mH },
## [M+H]+ to [2M+ACN+Na]+
function(mass){ (mass - mH) * 2 + mACN + mNa },
## [M+H]+ to [2M+3*H2O+2*H]2+
function(mass){((mass - mH) * 2 + 3 * mH2O + 2 * mH) / 2 },
## [M+H]+ to [M+2*H]2+
function(mass){ (mass + mH) / 2 },
## [M+H]+ to [M+H+NH4]2+
function(mass){ (mass + mNH4) / 2 },
## [M+H]+ to [M+H+Na]2+
function(mass){ (mass + mNa) / 2 },
## [M+H]+ to [M+H+K]2+
function(mass){ (mass + mK) / 2 },
## [M+H]+ to [M+ACN+2*H]2+
function(mass){ (mass + mACN + mH) / 2 },
## [M+H]+ to [M+2*Na]2+
function(mass){ (mass - mH + 2 * mNa) / 2 },
## [M+H]+ to [M+2*ACN+2*H]2+
function(mass){ (mass + 2 * mACN + mH) / 2 },
## [M+H]+ to [M+3*ACN+2*H]2+
function(mass){ (mass + 3 * mACN + mH) / 2 },
## [M+H]+ to [M+3*H]3+
function(mass){ (mass + 2 * mH) / 3 },
## [M+H]+ to [M+2*H+Na]3+
function(mass){ (mass + mH + mNa) / 3 },
## [M+H]+ to [M+H+2*Na]3+
function(mass){ (mass + 2 * mNa) / 3 },
## [M+H]+ to [M+3*Na]3+
function(mass){ (mass - mH + 3 * mNa) / 3 }
))
},
"negative" = {
adductPopulationMz <- unlist(c(
## [M-H]+ to [M-H]+ (Reference)
## [M-H]+ to [M-H2O-H]+
function(mass){ mass - mH2O },
## [M-H]+ to [M+Na-2*H]+
function(mass){ mass - mH + mNa },
## [M-H]+ to [M+Cl]+
function(mass){ mass + mH + mCl },
## [M-H]+ to [M+K-2*H]+
function(mass){ mass - mH + mK },
## [M-H]+ to [M+FA-H]+
function(mass){ mass + mFA },
## [M-H]+ to [M+HAc-H]+
function(mass){ mass + mHAc },
## [M-H]+ to [M+Br]+
function(mass){ mass + mH + mBr },
## [M-H]+ to [M+TFA-H]+
function(mass){ mass + mTFA },
## [M-H]+ to [2M-H]+
function(mass){ (mass + mH) * 2 - mH },
## [M-H]+ to [2M+FA-H]+
function(mass){ (mass + mH) * 2 + mFA - mH },
## [M-H]+ to [2M+HAc-H]+
function(mass){ (mass + mH) * 2 + mHAc - mH },
## [M-H]+ to [3M-H]+
function(mass){ (mass + mH) * 3 - mH },
## [M-H]+ to [M-2*H]2+
function(mass){ (mass - mH) / 2 },
## [M-H]+ to [M-3*H]3+
function(mass){ (mass - 2 * mH) / 3 }
))
},
"unknown"={
warning("Unknown polarity! No adduct ROIs have been added.")
},
stop("Unknown polarity (", polarity, ")!")
)
req_cols <- c("mz", "mzmin", "mzmax", "scmin", "scmax", "scale")
roiL <- split(peaks.[, req_cols, drop = FALSE], f = 1:nrow(peaks.))
newRois <- lapply(roiL, function(z) {
mzDiff <- unlist(lapply(adductPopulationMz, function(x) {
do.call(x, list(mass = z[1]))
}))
return(cbind(mz = z[1] + mzDiff,
mzmin = z[2] + mzDiff,
mzmax = z[3] + mzDiff,
scmin = z[4],
scmax = z[5],
length = -1,
intensity = -1,
scale = z[6]))
})
newRois <- do.call(rbind, newRois)
## Remove ROIs with negative or zero mzmin.
return(newRois[newRois[, "mzmin"] > 0, , drop = FALSE])
}
############################################################
## do_findKalmanROI
do_findKalmanROI <- function(mz, int, scantime, valsPerSpect,
mzrange = c(0.0, 0.0),
scanrange = c(1, length(scantime)),
minIntensity, minCentroids, consecMissedLim,
criticalVal, ppm, segs, scanBack) {
if (missing(mz) | missing(int) | missing(scantime) | missing(valsPerSpect))
stop("Arguments 'mz', 'int', 'scantime' and 'valsPerSpect'",
" are required!")
if (length(mz) != length(int) | length(valsPerSpect) != length(scantime)
| length(mz) != sum(valsPerSpect))
stop("Lengths of 'mz', 'int' and of 'scantime','valsPerSpect'",
" have to match. Also, 'length(mz)' should be equal to",
" 'sum(valsPerSpect)'.")
scanindex <- valueCount2ScanIndex(valsPerSpect) ## Get index vector for C calls
## Call the C function.
if (!is.double(mz))
mz <- as.double(mz)
if (!is.double(int))
int <- as.double(int)
if (!is.integer(scanindex))
scanindex <- as.integer(scanindex)
if (!is.double(scantime))
scantime <- as.double(scantime)
tmp <- capture.output(
res <- .Call("massifquant", mz, int, scanindex, scantime,
as.double(mzrange), as.integer(scanrange),
as.integer(length(scantime)), as.double(minIntensity),
as.integer(minCentroids), as.double(consecMissedLim),
as.double(ppm), as.double(criticalVal), as.integer(segs),
as.integer(scanBack), PACKAGE ='xcms' )
)
res
}
############################################################
## do_findChromPeaks_centWaveWithPredIsoROIs
## 1) Run a centWave.
## 2) Predict isotope ROIs for the identified peaks.
## 3) centWave on the predicted isotope ROIs.
## 4) combine both lists of identified peaks removing overlapping ones by
## keeping the peak with the largest signal intensity.
#' @title Core API function for two-step centWave peak detection with isotopes
#'
#' @description The \code{do_findChromPeaks_centWaveWithPredIsoROIs} performs a
#' two-step centWave based peak detection: chromatographic peaks are
#' identified using centWave followed by a prediction of the location of
#' the identified peaks' isotopes in the mz-retention time space. These
#' locations are fed as \emph{regions of interest} (ROIs) to a subsequent
#' centWave run. All non overlapping peaks from these two peak detection
#' runs are reported as the final list of identified peaks.
#'
#' @details For more details on the centWave algorithm see
#' \code{\link{centWave}}.
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @inheritParams findChromPeaks-centWaveWithPredIsoROIs
#'
#' @inheritParams do_findChromPeaks_centWave
#'
#' @family core peak detection functions
#'
#' @return A matrix, each row representing an identified chromatographic peak.
#' All non-overlapping peaks identified in both centWave runs are reported.
#' The matrix columns are:
#' \describe{
#' \item{mz}{Intensity weighted mean of m/z values of the peaks across scans.}
#' \item{mzmin}{Minimum m/z of the peaks.}
#' \item{mzmax}{Maximum m/z of the peaks.}
#' \item{rt}{Retention time of the peak's midpoint.}
#' \item{rtmin}{Minimum retention time of the peak.}
#' \item{rtmax}{Maximum retention time of the peak.}
#' \item{into}{Integrated (original) intensity of the peak.}
#' \item{intb}{Per-peak baseline corrected integrated peak intensity.}
#' \item{maxo}{Maximum intensity of the peak.}
#' \item{sn}{Signal to noise ratio, defined as \code{(maxo - baseline)/sd},
#' \code{sd} being the standard deviation of local chromatographic noise.}
#' \item{egauss}{RMSE of Gaussian fit.}
#' }
#' Additional columns for \code{verboseColumns = TRUE}:
#' \describe{
#' \item{mu}{Gaussian parameter mu.}
#' \item{sigma}{Gaussian parameter sigma.}
#' \item{h}{Gaussian parameter h.}
#' \item{f}{Region number of the m/z ROI where the peak was localized.}
#' \item{dppm}{m/z deviation of mass trace across scans in ppm.}
#' \item{scale}{Scale on which the peak was localized.}
#' \item{scpos}{Peak position found by wavelet analysis (scan number).}
#' \item{scmin}{Left peak limit found by wavelet analysis (scan number).}
#' \item{scmax}{Right peak limit found by wavelet analysis (scan numer).}
#' }
#'
#' @rdname do_findChromPeaks_centWaveWithPredIsoROIs
#'
#' @author Hendrik Treutler, Johannes Rainer
do_findChromPeaks_centWaveWithPredIsoROIs <-
function(mz, int, scantime, valsPerSpect, ppm = 25, peakwidth = c(20, 50),
snthresh = 10, prefilter = c(3, 100), mzCenterFun = "wMean",
integrate = 1, mzdiff = -0.001, fitgauss = FALSE, noise = 0,
verboseColumns = FALSE, roiList = list(),
firstBaselineCheck = TRUE, roiScales = NULL, snthreshIsoROIs = 6.25,
maxCharge = 3, maxIso = 5, mzIntervalExtension = TRUE,
polarity = "unknown", extendLengthMSW = FALSE) {
## Input argument checking: most of it will be done in
## do_findChromPeaks_centWave
polarity <- match.arg(polarity, c("positive", "negative", "unknown"))
## 1) First centWave
feats_1 <- do_findChromPeaks_centWave(mz = mz, int = int,
scantime = scantime,
valsPerSpect = valsPerSpect,
ppm = ppm,
peakwidth = peakwidth,
snthresh = snthresh,
prefilter = prefilter,
mzCenterFun = mzCenterFun,
integrate = integrate,
mzdiff = mzdiff, fitgauss = fitgauss,
noise = noise,
verboseColumns = TRUE,
roiList = roiList,
firstBaselineCheck = firstBaselineCheck,
roiScales = roiScales,
extendLengthMSW = extendLengthMSW)
return(do_findChromPeaks_addPredIsoROIs(mz = mz, int = int,
scantime = scantime,
valsPerSpect = valsPerSpect,
ppm = ppm,
peakwidth = peakwidth,
snthresh = snthreshIsoROIs,
prefilter = prefilter,
mzCenterFun = mzCenterFun,
integrate = integrate,
mzdiff = mzdiff,
fitgauss = fitgauss,
noise = noise,
verboseColumns = verboseColumns,
peaks. = feats_1,
maxCharge = maxCharge,
maxIso = maxIso,
mzIntervalExtension = mzIntervalExtension,
polarity = polarity))
}
#' @description The \code{do_findChromPeaks_centWaveAddPredIsoROIs} performs
#' centWave based peak detection based in regions of interest (ROIs)
#' representing predicted isotopes for the peaks submitted with argument
#' \code{peaks.}. The function returns a matrix with the identified peaks
#' consisting of all input peaks and peaks representing predicted isotopes
#' of these (if found by the centWave algorithm).
#'
#' @param peaks. A matrix or \code{xcmsPeaks} object such as one returned by
#' a call to \code{link{do_findChromPeaks_centWave}} or
#' \code{link{findPeaks.centWave}} (both with \code{verboseColumns = TRUE})
#' with the peaks for which isotopes should be predicted and used for an
#' additional peak detectoin using the centWave method. Required columns
#' are: \code{"mz"}, \code{"mzmin"}, \code{"mzmax"}, \code{"scmin"},
#' \code{"scmax"}, \code{"scale"} and \code{"into"}.
#'
#' @param snthresh For \code{do_findChromPeaks_addPredIsoROIs}:
#' numeric(1) defining the signal to noise threshold for the centWave
#' algorithm. For \code{do_findChromPeaks_centWaveWithPredIsoROIs}:
#' numeric(1) defining the signal to noise threshold for the initial
#' (first) centWave run.
#'
#' @inheritParams findChromPeaks-centWave
#'
#' @inheritParams do_findChromPeaks_centWave
#'
#' @rdname do_findChromPeaks_centWaveWithPredIsoROIs
do_findChromPeaks_addPredIsoROIs <-
function(mz, int, scantime, valsPerSpect, ppm = 25, peakwidth = c(20, 50),
snthresh = 6.25, prefilter = c(3, 100), mzCenterFun = "wMean",
integrate = 1, mzdiff = -0.001, fitgauss = FALSE, noise = 0,
verboseColumns = FALSE, peaks. = NULL,
maxCharge = 3, maxIso = 5, mzIntervalExtension = TRUE,
polarity = "unknown") {
polarity <- match.arg(polarity, c("positive", "negative", "unknown"))
## These variables might at some point be added as function args.
addNewIsotopeROIs <- TRUE
addNewAdductROIs <- FALSE
## 2) predict isotope and/or adduct ROIs
f_mod <- peaks.
## Extend the mzmin and mzmax if needed.
tittle <- peaks.[, "mz"] * (ppm / 2) / 1E6
expand_mz <- (peaks.[, "mzmax"] - peaks.[, "mzmin"]) < (tittle * 2)
if (any(expand_mz)) {
f_mod[expand_mz, "mzmin"] <- peaks.[expand_mz, "mz"] -
tittle[expand_mz]
f_mod[expand_mz, "mzmax"] <- peaks.[expand_mz, "mz"] + tittle[expand_mz]
}
## Add predicted ROIs
if (addNewIsotopeROIs) {
iso_ROIs <- do_define_isotopes(peaks. = f_mod,
maxCharge = maxCharge,
maxIso = maxIso,
mzIntervalExtension = mzIntervalExtension)
} else {
iso_ROIs <- matrix(nrow = 0, ncol = 8)
colnames(iso_ROIs) <- c("mz", "mzmin", "mzmax", "scmin", "scmax",
"length", "intensity", "scale")
}
if (addNewAdductROIs) {
add_ROIs <- do_define_adducts(peaks. = f_mod, polarity = polarity)
} else {
add_ROIs <- matrix(nrow = 0, ncol = 8)
colnames(iso_ROIs) <- c("mz", "mzmin", "mzmax", "scmin", "scmax",
"length", "intensity", "scale")
}
newROIs <- rbind(iso_ROIs, add_ROIs)
rm(f_mod)
if (nrow(newROIs) == 0)
return(peaks.)
## Remove ROIs that are out of mz range:
mz_range <- range(mz)
newROIs <- newROIs[newROIs[, "mzmin"] >= mz_range[1] &
newROIs[, "mzmax"] <= mz_range[2], , drop = FALSE]
## Remove ROIs with too low signal:
keep_me <- logical(nrow(newROIs))
scanindex <- as.integer(valueCount2ScanIndex(valsPerSpect))
for (i in 1:nrow(newROIs)) {
vals <- .Call("getEIC", mz, int, scanindex,
as.double(newROIs[i, c("mzmin", "mzmax")]),
as.integer(newROIs[i, c("scmin", "scmax")]),
as.integer(length(scantime)), PACKAGE ='xcms' )
keep_me[i] <- sum(vals$intensity, na.rm = TRUE) >= 10
}
newROIs <- newROIs[keep_me, , drop = FALSE]
if (nrow(newROIs) == 0) {
warning("No isotope or adduct ROIs for the identified peaks with a ",
"valid signal found!")
return(peaks.)
}
## 3) centWave using the identified ROIs.
roiL <- split(as.data.frame(newROIs), f = 1:nrow(newROIs))
feats_2 <- do_findChromPeaks_centWave(mz = mz, int = int,
scantime = scantime,
valsPerSpect = valsPerSpect,
ppm = ppm, peakwidth = peakwidth,
snthresh = snthresh,
prefilter = prefilter,
mzCenterFun = mzCenterFun,
integrate = integrate,
mzdiff = mzdiff, fitgauss = fitgauss,
noise = noise,
verboseColumns = verboseColumns,
roiList = roiL,
firstBaselineCheck = FALSE,
roiScales = newROIs[, "scale"])
## Clean up of the results:
if (nrow(feats_2) > 0) {
## remove NaNs
any_na <- is.na(rowSums(feats_2[, c("mz", "mzmin", "mzmax", "rt",
"rtmin", "rtmax")]))
if (any(any_na))
feats_2 <- feats_2[!any_na, , drop = FALSE]
no_mz_width <- (feats_2[, "mzmax"] - feats_2[, "mzmin"]) == 0
no_rt_width <- (feats_2[, "rtmax"] - feats_2[, "rtmin"]) == 0
no_area <- no_mz_width | no_rt_width
if (any(no_area))
feats_2 <- feats_2[!no_area, , drop = FALSE]
}
## 4) Check and remove ROIs overlapping with peaks.
if (nrow(feats_2) > 0) {
## Comparing each ROI with each peak; slightly modified from the
## original code in which we prevent calling apply followed by
## two lapply.
## Update: we're no longer removing original peaks, as they are
## themselfs overlapping, thus we would remove too many.
removeROIs <- rep(FALSE, nrow(feats_2))
overlapProportionThreshold <- 0.01
for (i in 1:nrow(feats_2)) {
## Compare ROI i with all peaks (peaks) and check if its
## overlapping
## mz
roiMzCenter <- (feats_2[i, "mzmin"] + feats_2[i, "mzmax"]) / 2
peakMzCenter <- (peaks.[, "mzmin"] + peaks.[, "mzmax"]) / 2
roiMzRadius <- (feats_2[i, "mzmax"] - feats_2[i, "mzmin"]) / 2
peakMzRadius <- (peaks.[, "mzmax"] - peaks.[, "mzmin"]) / 2
overlappingMz <- abs(peakMzCenter - roiMzCenter) <=
(roiMzRadius + peakMzRadius)
## rt
roiRtCenter <- (feats_2[i, "rtmin"] + feats_2[i, "rtmax"]) / 2
peakRtCenter <- (peaks.[, "rtmin"] + peaks.[, "rtmax"]) / 2
roiRtRadius <- (feats_2[i, "rtmax"] - feats_2[i, "rtmin"]) / 2
peakRtRadius <- (peaks.[, "rtmax"] - peaks.[, "rtmin"]) / 2
overlappingRt <- abs(peakRtCenter - roiRtCenter) <=
(roiRtRadius + peakRtRadius)
is_overlapping <- overlappingMz & overlappingRt
## Now determine whether we remove the ROI or the peak,
## depending on the raw signal intensity.
if (any(is_overlapping)) {
if (any(peaks.[is_overlapping, "into"] >
feats_2[i, "into"]))
removeROIs[i] <- TRUE
}
}
feats_2 <- feats_2[!removeROIs, , drop = FALSE]
}
if (!verboseColumns)
peaks. <- peaks.[ , c("mz", "mzmin", "mzmax", "rt", "rtmin",
"rtmax", "into", "intb", "maxo", "sn")]
if (nrow(feats_2))
rbind(peaks., feats_2)
else
peaks.
}
do_findChromPeaks_addPredIsoROIs_mod <-
function(mz, int, scantime, valsPerSpect, ppm = 25, peakwidth = c(20, 50),
snthresh = 6.25, prefilter = c(3, 100), mzCenterFun = "wMean",
integrate = 1, mzdiff = -0.001, fitgauss = FALSE, noise = 0,
verboseColumns = FALSE, peaks. = NULL,
maxCharge = 3, maxIso = 5, mzIntervalExtension = TRUE,
polarity = "unknown") {
## Input argument checking: most of it will be done in
## do_findChromPeaks_centWave
polarity <- match.arg(polarity, c("positive", "negative", "unknown"))
## These variables might at some point be added as function args.
addNewIsotopeROIs <- TRUE
addNewAdductROIs <- FALSE
## 2) predict isotope and/or adduct ROIs
f_mod <- peaks.
## Extend the mzmin and mzmax if needed.
tittle <- peaks.[, "mz"] * (ppm / 2) / 1E6
expand_mz <- (peaks.[, "mzmax"] - peaks.[, "mzmin"]) < (tittle * 2)
if (any(expand_mz)) {
f_mod[expand_mz, "mzmin"] <- peaks.[expand_mz, "mz"] -
tittle[expand_mz]
f_mod[expand_mz, "mzmax"] <- peaks.[expand_mz, "mz"] + tittle[expand_mz]
}
## Add predicted ROIs
if (addNewIsotopeROIs) {
iso_ROIs <- do_define_isotopes(peaks. = f_mod,
maxCharge = maxCharge,
maxIso = maxIso,
mzIntervalExtension = mzIntervalExtension)
} else {
iso_ROIs <- matrix(nrow = 0, ncol = 8)
colnames(iso_ROIs) <- c("mz", "mzmin", "mzmax", "scmin", "scmax",
"length", "intensity", "scale")
}
if (addNewAdductROIs) {
add_ROIs <- do_define_adducts(peaks. = f_mod, polarity = polarity)
} else {
add_ROIs <- matrix(nrow = 0, ncol = 8)
colnames(iso_ROIs) <- c("mz", "mzmin", "mzmax", "scmin", "scmax",
"length", "intensity", "scale")
}
newROIs <- rbind(iso_ROIs, add_ROIs)
rm(f_mod)
if (nrow(newROIs) == 0)
return(peaks.)
## Remove ROIs that are out of mz range:
mz_range <- range(mz)
newROIs <- newROIs[newROIs[, "mzmin"] >= mz_range[1] &
newROIs[, "mzmax"] <= mz_range[2], , drop = FALSE]
## Remove ROIs with too low signal:
keep_me <- logical(nrow(newROIs))
scanindex <- as.integer(valueCount2ScanIndex(valsPerSpect))
for (i in 1:nrow(newROIs)) {
vals <- .Call("getEIC", mz, int, scanindex,
as.double(newROIs[i, c("mzmin", "mzmax")]),
as.integer(newROIs[i, c("scmin", "scmax")]),
as.integer(length(scantime)), PACKAGE ='xcms' )
keep_me[i] <- sum(vals$intensity, na.rm = TRUE) >= 10
}
newROIs <- newROIs[keep_me, , drop = FALSE]
if (nrow(newROIs) == 0) {
warning("No isotope or adduct ROIs for the identified peaks with a ",
"valid signal found!")
return(peaks.)
}
cat("No. of input peaks: ", nrow(peaks.), "\n")
## 3) centWave using the identified ROIs.
roiL <- split(as.data.frame(newROIs), f = 1:nrow(newROIs))
cat("Identified iso ROIs: ", length(roiL), "\n")
feats_2 <- do_findChromPeaks_centWave(mz = mz, int = int,
scantime = scantime,
valsPerSpect = valsPerSpect,
ppm = ppm, peakwidth = peakwidth,
snthresh = snthresh,
prefilter = prefilter,
mzCenterFun = mzCenterFun,
integrate = integrate,
mzdiff = mzdiff, fitgauss = fitgauss,
noise = noise,
verboseColumns = verboseColumns,
roiList = roiL,
firstBaselineCheck = FALSE,
roiScales = newROIs[, "scale"])
cat("No. of chrom. peaks found in ROIs: ", nrow(feats_2), "\n")
## Clean up of the results:
if (nrow(feats_2) > 0) {
## remove NaNs
any_na <- is.na(rowSums(feats_2[, c("mz", "mzmin", "mzmax", "rt",
"rtmin", "rtmax")]))
if (any(any_na))
feats_2 <- feats_2[!any_na, , drop = FALSE]
no_mz_width <- (feats_2[, "mzmax"] - feats_2[, "mzmin"]) == 0
no_rt_width <- (feats_2[, "rtmax"] - feats_2[, "rtmin"]) == 0
cat("No. of peaks with NA values: ", sum(any_na), "\n")
cat("No. of peaks without mz width: ", sum(no_mz_width), "\n")
cat("No. of peaks without rt width: ", sum(no_rt_width), "\n")
## remove empty area
## no_area <- (feats_2[, "mzmax"] - feats_2[, "mzmin"]) == 0 ||
## (feats_2[, "rtmax"] - feats_2[, "rtmin"]) == 0
## no_area <- no_mz_width || no_rt_width
no_area <- no_mz_width
if (any(no_area))
feats_2 <- feats_2[!no_area, , drop = FALSE]
}
cat("After removing NAs or empty are peaks: ", nrow(feats_2), "\n")
## 4) Check and remove ROIs overlapping with peaks.
if (nrow(feats_2) > 0) {
## Comparing each ROI with each peak; slightly modified from the original
## code in which we prevent calling apply followed by two lapply.
removeROIs <- rep(FALSE, nrow(feats_2))
removeFeats <- rep(FALSE, nrow(peaks.))
overlapProportionThreshold <- 0.01
for (i in 1:nrow(feats_2)) {
## Compare ROI i with all peaks (peaks) and check if its
## overlapping
## mz
roiMzCenter <- (feats_2[i, "mzmin"] + feats_2[i, "mzmax"]) / 2
peakMzCenter <- (peaks.[, "mzmin"] + peaks.[, "mzmax"]) / 2
roiMzRadius <- (feats_2[i, "mzmax"] - feats_2[i, "mzmin"]) / 2
peakMzRadius <- (peaks.[, "mzmax"] - peaks.[, "mzmin"]) / 2
overlappingMz <- abs(peakMzCenter - roiMzCenter) <=
(roiMzRadius + peakMzRadius)
## rt
roiRtCenter <- (feats_2[i, "rtmin"] + feats_2[i, "rtmax"]) / 2
peakRtCenter <- (peaks.[, "rtmin"] + peaks.[, "rtmax"]) / 2
roiRtRadius <- (feats_2[i, "rtmax"] - feats_2[i, "rtmin"]) / 2
peakRtRadius <- (peaks.[, "rtmax"] - peaks.[, "rtmin"]) / 2
overlappingRt <- abs(peakRtCenter - roiRtCenter) <=
(roiRtRadius + peakRtRadius)
is_overlapping <- overlappingMz & overlappingRt
## Now determine whether we remove the ROI or the peak, depending
## on the raw signal intensity.
if (any(is_overlapping)) {
if (any(peaks.[is_overlapping, "into"] > feats_2[i, "into"])) {
removeROIs[i] <- TRUE
} else {
removeFeats[is_overlapping] <- TRUE
}
}
}
feats_2 <- feats_2[!removeROIs, , drop = FALSE]
peaks. <- peaks.[!removeFeats, , drop = FALSE]
}
cat("After removing overlapping peaks: ", nrow(feats_2), "\n")
cat("After removing overlapping peaks (peaks.): ", nrow(peaks.), "\n")
if (!verboseColumns)
peaks. <- peaks.[ , c("mz", "mzmin", "mzmax", "rt", "rtmin",
"rtmax", "into", "intb", "maxo", "sn")]
## For now just return the new ones.
return(feats_2)
if (nrow(feats_2) == 0)
return(peaks.)
else
return(rbind(peaks., feats_2))
}
#' @title Identify peaks in chromatographic data using matchedFilter
#'
#' @description
#'
#' The function performs peak detection using the [matchedFilter] algorithm
#' on chromatographic data (i.e. with only intensities and retention time).
#'
#' @param int `numeric` with intensity values.
#'
#' @param rt `numeric` with the retention time for the intensities. Length has
#' to be equal to `length(int)`.
#'
#' @param fwhm `numeric(1)` specifying the full width at half maximum
#' of matched filtration gaussian model peak. Only used to calculate the
#' actual sigma, see below.
#'
#' @param sigma `numeric(1)` specifying the standard deviation (width)
#' of the matched filtration model peak.
#'
#' @param max `numeric(1)` with the maximal number of peaks that are expected/
#' will bbe detected in the data
#'
#' @param snthresh `numeric(1)` defining the signal to noise cut-off to be used
#' in the peak detection step.
#'
#' @param ... currently ignored.
#'
#' @family peak detection functions for chromatographic data
#'
#' @seealso [matchedFilter] for a detailed description of the peak detection
#' method.
#'
#' @author Johannes Rainer
#'
#' @return
#'
#' A matrix, each row representing an identified chromatographic peak, with
#' columns:
#'
#' - `"rt"`: retention time of the peak's midpoint (time of the maximum signal).
#' - `"rtmin"`: minimum retention time of the peak.
#' - `"rtmax"`: maximum retention time of the peak.
#' - `"into"`: integrated (original) intensity of the peak.
#' - `"intf"`: integrated intensity of the filtered peak.
#' - `"maxo"`: maximum (original) intensity of the peak.
#' - `"maxf"`" maximum intensity of the filtered peak.
#' - `"sn"`: signal to noise ratio of the peak.
#'
#' @md
#'
#' @examples
#'
#' ## Load the test file
#' data(faahko_sub)
#' ## Update the path to the files for the local system
#' dirname(faahko_sub) <- system.file("cdf/KO", package = "faahKO")
#'
#' ## Subset to one file and drop identified chromatographic peaks
#' data <- dropChromPeaks(filterFile(faahko_sub, 1))
#'
#' ## Extract chromatographic data for a small m/z range
#' chr <- chromatogram(data, mz = c(272.1, 272.3), rt = c(3000, 3200))[1, 1]
#'
#' pks <- peaksWithMatchedFilter(intensity(chr), rtime(chr))
#' pks
#'
#' ## Plotting the data
#' plot(rtime(chr), intensity(chr), type = "h")
#' rect(xleft = pks[, "rtmin"], xright = pks[, "rtmax"], ybottom = c(0, 0),
#' ytop = pks[, "maxo"], border = "red")
peaksWithMatchedFilter <- function(int, rt, fwhm = 30, sigma = fwhm / 2.3548,
max = 20, snthresh = 10, ...) {
if (missing(int) | missing(rt))
stop("Arguments 'int' and 'rt' are required")
if (length(int) != length(rt))
stop("'int' and 'rt' must have the same length")
## Replace NAs with 0 - that's how the original code handled it.
nas <- is.na(int)
int[nas] <- 0
n_vals <- length(int)
N <- nextn(n_vals)
rtrange <- range(rt)
x <- c(0:(N / 2), -(ceiling(N / 2 - 1)):-1) *
(rtrange[2] - rtrange[1]) / (n_vals - 1)
filt <- -attr(eval(deriv3(~ 1 / (sigma * sqrt(2 * pi)) *
exp(-x^2 / (2 * sigma^2)), "x")),
"hessian")
filt <- filt / sqrt(sum(filt^2))
filt <- fft(filt, inverse = TRUE) / length(filt)
cnames <- c("rt", "rtmin", "rtmax", "into", "intf", "maxo", "maxf", "sn")
num <- 0
ResList <- list()
int_filt <- filtfft(int, filt)
glob_max <- max(int_filt)
for (j in seq(length = max)) {
max_idx <- which.max(int_filt)
noise <- mean(int[int > 0])
##noise <- mean(yfilt[yfilt >= 0])
sn <- int_filt[max_idx] / noise
if (int_filt[max_idx] > 0 && int_filt[max_idx] > snthresh * noise &&
int[max_idx] > 0) {
peak_range <- descendZero(int_filt, max_idx)
peak_range_idx <- peak_range[1]:peak_range[2]
## Define into and intf, i.e. the integrated signal.
peak_width <- diff(rt[peak_range]) / diff(peak_range)
into <- peak_width * sum(int[peak_range_idx])
intf <- peak_width * sum(int_filt[peak_range_idx])
num <- num + 1
ResList[[num]] <- c(rt[max_idx], rt[peak_range], into, intf,
max(int[peak_range_idx]), int_filt[max_idx], sn)
## "remove" current peak from the data
int_filt[peak_range_idx] <- 0
} else
break
}
if (length(ResList)) {
res <- do.call(rbind, ResList)
colnames(res) <- cnames
} else {
warning("No peaks found with current settings")
res <- matrix(nrow = 0, ncol = length(cnames),
dimnames = list(character(), cnames))
}
res
}
#' @title Identify peaks in chromatographic data using centWave
#'
#' @description
#'
#' `peaksWithCentWave` identifies (chromatographic) peaks in purely
#' chromatographic data, i.e. based on intensity and retention time values
#' without m/z values.
#'
#' @details
#'
#' The method uses the same algorithm for the peak detection than [centWave],
#' employs however a different approach to identify the initial regions in
#' which the peak detection is performed (i.e. the *regions of interest* ROI).
#' The method first identifies all local maxima in the chromatographic data and
#' defines the corresponding positions +/- `peakwidth[2]` as the ROIs. Noise
#' estimation bases also on these ROIs and can thus be different from [centWave]
#' resulting in different signal to noise ratios.
#'
#' @param int `numeric` with intensity values.
#'
#' @param rt `numeric` with the retention time for the intensities. Length has
#' to be equal to `length(int)`.
#'
#' @param peakwidth `numeric(2)` with the lower and upper bound of the
#' expected peak width.
#'
#' @param snthresh `numeric(1)` defining the signal to noise ratio cutoff.
#' Peaks with a signal to noise ratio < `snthresh` are omitted.
#'
#' @param prefilter `numeric(2)` (`c(k, I)`): only regions of interest with at
#' least `k` centroids with signal `>= I` are returned in the first
#' step.
#'
#' @param integrate `numeric(1)`, integration method. For `integrate = 1` peak
#' limits are found through descending on the mexican hat filtered data,
#' for `integrate = 2` the descend is done on the real data. The latter
#' method is more accurate but prone to noise, while the former is more
#' robust, but less exact.
#'
#' @param fitgauss `logical(1)` whether or not a Gaussian should be fitted
#' to each peak.
#'
#' @param noise `numeric(1)` defining the minimum required intensity for
#' centroids to be considered in the first analysis step (definition of
#' the *regions of interest*).
#'
#' @param verboseColumns `logical(1)`: whether additional peak meta data
#' columns should be returned.
#'
#' @param firstBaselineCheck `logical(1)`. If `TRUE` continuous data within
#' regions of interest is checked to be above the first baseline.
#'
#' @param extendLengthMSW `logical(1)`. If `TRUE` the "open" method of EIC
#' extension is used, rather than the default "reflect" method.
#'
#' @param ... currently ignored.
#'
#' @family peak detection functions for chromatographic data
#'
#' @seealso [centWave] for a detailed description of the peak detection
#' method.
#'
#' @author Johannes Rainer
#'
#' @return
#'
#' A matrix, each row representing an identified chromatographic peak, with
#' columns:
#'
#' - `"rt"`: retention time of the peak's midpoint (time of the maximum signal).
#' - `"rtmin"`: minimum retention time of the peak.
#' - `"rtmax"`: maximum retention time of the peak.
#' - `"into"`: integrated (original) intensity of the peak.
#' - `"intb"`: per-peak baseline corrected integrated peak intensity.
#' - `"maxo"`: maximum (original) intensity of the peak.
#' - `"sn"`: signal to noise ratio of the peak defined as
#' `(maxo - baseline)/sd` with `sd` being the standard deviation of the local
#' chromatographic noise.
#'
#' Additional columns for `verboseColumns = TRUE`:
#'
#' - `"mu"`: gaussian parameter mu.
#' - `"sigma"`: gaussian parameter sigma.
#' - `"h"`: gaussian parameter h.
#' - `"f"`: region number of the m/z ROI where the peak was localized.
#' - `"dppm"`: m/z deviation of mass trace across scans in ppm (always `NA`).
#' - `"scale"`: scale on which the peak was localized.
#' - `"scpos"`: peak position found by wavelet analysis (index in `int`).
#' - `"scmin"`: left peak limit found by wavelet analysis (index in `int`).
#' - `"scmax"`: right peak limit found by wavelet analysis (index in `int`).
#'
#' @md
#'
#' @examples
#'
#' ## Reading a file
#' library(xcms)
#' od <- readMSData(system.file("cdf/KO/ko15.CDF", package = "faahKO"),
#' mode = "onDisk")
#'
#' ## Extract chromatographic data for a small m/z range
#' mzr <- c(272.1, 272.2)
#' chr <- chromatogram(od, mz = mzr, rt = c(3000, 3300))[1, 1]
#'
#' int <- intensity(chr)
#' rt <- rtime(chr)
#'
#' ## Plot the region
#' plot(chr, type = "h")
#'
#' ## Identify peaks in the chromatographic data
#' pks <- peaksWithCentWave(intensity(chr), rtime(chr))
#' pks
#'
#' ## Highlight the peaks
#' rect(xleft = pks[, "rtmin"], xright = pks[, "rtmax"],
#' ybottom = rep(0, nrow(pks)), ytop = pks[, "maxo"], col = "#ff000040",
#' border = "#00000040")
peaksWithCentWave <- function(int, rt,
peakwidth = c(20, 50),
snthresh = 10,
prefilter = c(3, 100),
integrate = 1,
fitgauss = FALSE,
noise = 0, ## noise.local=TRUE,
verboseColumns = FALSE,
firstBaselineCheck = TRUE,
extendLengthMSW = FALSE,
...
) {
if (length(peakwidth) != 2)
stop("'peakwidth' has to be a numeric of length 2")
## Avoid NAs
int[is.na(int)] <- 0
rois <- .getRtROI(int, rt, peakwidth = peakwidth, noise = noise,
prefilter = prefilter)
basenames <- c("mz", "mzmin", "mzmax", "rt", "rtmin", "rtmax", "into",
"intb", "maxo", "sn")
verbosenames <- c("egauss", "mu", "sigma", "h", "f", "dppm", "scale",
"scpos", "scmin", "scmax", "lmin", "lmax")
peaks_names <- c(basenames, verbosenames)
peaks_ncols <- length(peaks_names)
peakinfo_names <- c("scale", "scaleNr", "scpos", "scmin", "scmax")
## Peak width: seconds to scales
scalerange <- round((peakwidth / mean(diff(rt))) / 2)
if (length(z <- which(scalerange == 0)))
scalerange <- scalerange[-z]
if (length(scalerange) < 1) {
warning("No scales? Please check peak width!")
if (verboseColumns)
basenames <- c(basenames, verbosenames)
return(invisible(
matrix(nrow = 0, ncol = length(basenames),
dimnames = list(character(), basenames))[, -(1:3), drop = FALSE]))
}
if (length(scalerange) > 1)
scales <- seq(from = scalerange[1], to = scalerange[2], by = 2)
else
scales <- scalerange
minPeakWidth <- scales[1]
noiserange <- c(ceiling(minPeakWidth) * 3, max(scales) * 3)
maxGaussOverlap <- 0.5
minPtsAboveBaseLine <- max(4, minPeakWidth - 2)
minCentroids <- minPtsAboveBaseLine
scRangeTol <- maxDescOutlier <- floor(minPeakWidth / 2)
scanrange <- c(1, length(rt))
Nscantime <- length(int)
## mzdiff <- -0.001
mzdiff <- 0
peaklist <- NULL
for (i in seq_len(nrow(rois))) {
scmin <- rois[i, "scmin"]
scmax <- rois[i, "scmax"]
N <- scmax - scmin + 1
peaks <- matrix(ncol = peaks_ncols, nrow = 0,
dimnames = list(character(), peaks_names))
peakinfo <- matrix(ncol = 5, nrow = 0,
dimnames = list(character(), peakinfo_names))
## Could also return the "correct one..."
sccenter <- scmin + floor(N/2) - 1
## sccenter <- rois[i, "sccent"]
scrange <- c(scmin, scmax)
## scrange + noiserange, used for baseline detection and wavelet analysis
sr <- c(max(scanrange[1], scrange[1] - max(noiserange)),
min(scanrange[2], scrange[2] + max(noiserange)))
## Intensities for baseline detection and wavelet analysis
td <- sr[1]:sr[2]
d <- int[td]
scan.range <- c(sr[1], sr[2])
## the ROI
otd <- scmin:scmax
od <- int[otd]
if (all(od == 0)) {
warning("centWave: no peaks found in ROI.")
next
}
## scrange + scRangeTol, used for gauss fitting and continuous
## data above 1st baseline detection
ftd <- max(td[1], scrange[1] - scRangeTol):min(td[length(td)],
scrange[2] + scRangeTol)
fd <- int[ftd]
## 1st type of baseline: statistic approach
## in case of very long mass trace use full scan range
## for baseline detection
if (N >= 10 * minPeakWidth) {
noised <- int
} else {
noised <- d
}
## 90% trimmed mean as first baseline guess
noise <- xcms:::estimateChromNoise(noised, trim = 0.05,
minPts = 3 * minPeakWidth)
## any continuous data above 1st baseline ?
if (firstBaselineCheck &
!continuousPtsAboveThreshold(fd, threshold = noise,
num = minPtsAboveBaseLine))
next
## 2nd baseline estimate using not-peak-range
lnoise <- xcms:::getLocalNoiseEstimate(d, td, ftd, noiserange, Nscantime,
threshold = noise,
num = minPtsAboveBaseLine)
## Final baseline & Noise estimate
baseline <- max(1, min(lnoise[1], noise))
sdnoise <- max(1, lnoise[2])
sdthr <- sdnoise * snthresh
## is there any data above S/N * threshold ?
if (!(any(fd - baseline >= sdthr)))
next
wCoefs <- xcms:::MSW.cwt(d, scales = scales, wavelet = 'mexh',
extendLengthMSW = extendLengthMSW)
if (!(!is.null(dim(wCoefs)) && any((wCoefs - baseline) >= sdthr)))
next
if (td[length(td)] == Nscantime) ## workaround, localMax fails otherwise
wCoefs[nrow(wCoefs),] <- wCoefs[nrow(wCoefs) - 1, ] * 0.99
localMax <- xcms:::MSW.getLocalMaximumCWT(wCoefs)
rL <- xcms:::MSW.getRidge(localMax)
wpeaks <- sapply(rL,
function(x) {
w <- min(1:length(x), ncol(wCoefs))
any((wCoefs[x,w] - baseline) >= sdthr)
})
if (any(wpeaks)) {
wpeaksidx <- which(wpeaks)
## check each peak in ridgeList
for (p in 1:length(wpeaksidx)) {
opp <- rL[[wpeaksidx[p]]]
pp <- unique(opp) ## NOTE: this is not ordered!
if (length(pp) >= 1) {
dv <- td[pp] %in% ftd
if (any(dv)) { ## peaks in orig. data range
## Final S/N check
if (any(d[pp[dv]] - baseline >= sdthr)) {
## ## allow roiScales to be a numeric of length 0
## if(length(roiScales) > 0) {
## ## use given scale
## best.scale.nr <- which(scales == roiScales[[f]])
## if(best.scale.nr > length(opp))
## best.scale.nr <- length(opp)
## } else {
## try to decide which scale describes the peak best
inti <- numeric(length(opp))
irange <- rep(ceiling(scales[1]/2), length(opp))
for (k in 1:length(opp)) {
kpos <- opp[k]
r1 <- ifelse(kpos - irange[k] > 1,
kpos - irange[k], 1)
r2 <- ifelse(kpos + irange[k] < length(d),
kpos + irange[k], length(d))
inti[k] <- sum(d[r1:r2])
}
maxpi <- which.max(inti)
if (length(maxpi) > 1) {
m <- wCoefs[opp[maxpi], maxpi]
bestcol <- which(m == max(m),
arr.ind = TRUE)[2]
best.scale.nr <- maxpi[bestcol]
} else {
best.scale.nr <- maxpi
}
best.scale <- scales[best.scale.nr]
best.scale.pos <- opp[best.scale.nr]
pprange <- min(pp):max(pp)
lwpos <- max(1, best.scale.pos - best.scale)
rwpos <- min(best.scale.pos + best.scale, length(td))
p1 <- match(td[lwpos], otd)[1]
p2 <- match(td[rwpos], otd)
p2 <- p2[length(p2)]
if (is.na(p1)) p1 <- 1
if (is.na(p2)) p2 <- N
maxint <- max(od[p1:p2])
peaks <- rbind(
peaks,
c(1, 1, 1, # mz, mzmin, mzmax,
NA, NA, NA, # rt, rtmin, rtmax,
NA, # intensity (sum)
NA, # intensity (-bl)
maxint, # max intensity
round((maxint - baseline) / sdnoise), # S/N Ratio
NA, # Gaussian RMSE
NA,NA,NA, # Gaussian Parameters
i, # ROI Position
NA, # max. difference between the [minCentroids] peaks in ppm
best.scale, # Scale
td[best.scale.pos],
td[lwpos],
td[rwpos], # Peak positions guessed from the wavelet's (scan nr)
NA, NA)) # Peak limits (scan nr)
peakinfo <- rbind(
peakinfo,
c(best.scale, best.scale.nr,
best.scale.pos, lwpos, rwpos))
## Peak positions guessed from the wavelet's
}
}
}
} # for (p in 1:length(wpeaksidx))
} # if (any(wpeaks))
## postprocessing
for (p in seq_len(nrow(peaks))) {
## find minima, assign rt and intensity values
if (integrate == 1) {
lm <- xcms:::descendMin(wCoefs[, peakinfo[p, "scaleNr"]],
istart = peakinfo[p, "scpos"])
gap <- all(d[lm[1]:lm[2]] == 0) # looks like we got stuck in a gap right in the middle of the peak
if ((lm[1] == lm[2]) || gap ) # fall-back
lm <- xcms:::descendMinTol(d, startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
} else {
lm <- xcms:::descendMinTol(d, startpos = c(peakinfo[p, "scmin"],
peakinfo[p, "scmax"]),
maxDescOutlier)
}
## Narrow down peak rt boundaries by removing values below cut-off
lm <- .narrow_rt_boundaries(lm, d)
lm_range <- lm[1]:lm[2]
pd <- d[lm_range]
peakrange <- td[lm]
peaks[p, "rtmin"] <- rt[peakrange[1]]
peaks[p, "rtmax"] <- rt[peakrange[2]]
peaks[p, "maxo"] <- max(pd)
pwid <- (rt[peakrange[2]] - rt[peakrange[1]]) /
(peakrange[2] - peakrange[1])
if (is.na(pwid))
pwid <- 1
peaks[p, "into"] <- pwid * sum(pd)
db <- pd - baseline
peaks[p, "intb"] <- pwid * sum(db[db>0])
peaks[p, "lmin"] <- lm[1]
peaks[p, "lmax"] <- lm[2]
if (fitgauss) {
## perform gaussian fits, use wavelets for inital parameters
td_lm <- td[lm_range]
md <- max(pd)
d1 <- pd / md ## normalize data for gaussian error calc.
pgauss <- fitGauss(td_lm, pd,
pgauss = list(mu = peaks[p, "scpos"],
sigma = peaks[p, "scmax"] -
peaks[p, "scmin"],
h = peaks[p, "maxo"]))
rtime <- peaks[p, "scpos"]
if (!any(is.na(pgauss)) && all(pgauss > 0)) {
gtime <- td[match(round(pgauss$mu), td)]
if (!is.na(gtime)) {
rtime <- gtime
peaks[p, "mu"] <- pgauss$mu
peaks[p, "sigma"] <- pgauss$sigma
peaks[p, "h"] <- pgauss$h
peaks[p,"egauss"] <- sqrt(
(1 / length(td_lm)) *
sum(((d1 - gauss(td_lm, pgauss$h / md,
pgauss$mu, pgauss$sigma))^2)))
}
}
peaks[p, "rt"] <- rt[rtime]
## avoid fitting side effects
if (peaks[p, "rt"] < peaks[p, "rtmin"])
peaks[p, "rt"] <- rt[peaks[p, "scpos"]]
} else {
peaks[p, "rt"] <- rt[peaks[p, "scpos"]]
}
} # end for (p in seq_len(nrow(peaks)))
peaks <- joinOverlappingPeaks(td, d, otd, rep(1, length(otd)), od, rt,
scan.range, peaks, maxGaussOverlap,
mzCenterFun = mzCenter.wMean)
if (!is.null(peaks))
peaklist[[length(peaklist) + 1]] <- peaks
} # end of for (i in seq_len(nrow(rois)))
if (length(peaklist) == 0) {
warning("No peaks found!")
if (verboseColumns)
nopeaks <- matrix(nrow = 0, ncol = peaks_ncols,
dimnames = list(character(), peaks_names))
else
nopeaks <- matrix(nrow = 0, ncol = length(basenames),
dimnames = list(character(), basenames))
return(nopeaks[, -(1:3), drop = FALSE])
}
p <- do.call(rbind, peaklist)
if (!verboseColumns)
p <- p[, basenames, drop = FALSE]
uorder <- order(p[, "into"], decreasing = TRUE)
pm <- p[, c("mzmin", "mzmax", "rtmin", "rtmax"), drop = FALSE]
uindex <- rectUnique(pm, uorder, mzdiff, ydiff = -0.00001) # allow adjacent peaks
unique(p[uindex, -(1:3), drop = FALSE])
}
#' @description
#'
#' Identify regions in the intensity vector in which we might expect a peak.
#' In contrast to the original `.Call("findmzROI")` we base the search
#' exclusively on the intensity values, first identifying local maxima in a
#' moving window approach based on the lower expected peak width
#' (`peakwidth[1]`) and subsequently defining regions with width equal to
#' `peakwidth[2]` centered around the local maxima.
#'
#' @param int `numeric` with the intensities. Should **not** contain `NA`s!
#'
#' @param rt `numeric` with the retention times.
#'
#' @param peakwidth `numeric(2)` with the lowe and upper bound for the expected
#' peak widths.
#'
#' @param prefilter `numeric(2)` (`c(k, I)`): only regions of interest with at
#' least `k` centroids with signal `>= I` are returned.
#'
#' @param noise `numeric(1)` defining the minimum required intensity for
#' centroids to be considered in the first analysis step.
#'
#' @return `matrix` with two columns `"scmin"`, `"scmax"` and `"sccent"` with
#' the index of (lower and upper) bound defining the region of interest and
#' the position of the center.
#'
#' @md
#'
#' @noRd
#'
#' @examples
#'
#' library(xcms)
#' od <- readMSData(system.file("cdf/KO/ko15.CDF", package = "faahKO"),
#' mode = "onDisk")
#'
#' ## Extract chromatographic data for a small m/z range
#' chr <- chromatogram(od, mz = c(272.1, 272.3))[1, 1]
#'
#' int <- intensity(chr)
#' int[is.na(int)] <- 0
#' rt <- rtime(chr)
#' .getRtROI(int, rt)
.getRtROI <- function(int, rt, peakwidth = c(20, 50), noise = 0,
prefilter = c(3, 100)) {
peakwidth <- range(peakwidth)
if (length(prefilter) != 2)
stop("'prefilter' has to be a 'numeric' of length 2")
int_len <- length(int)
if (int_len != length(rt))
stop("lengths of 'int' and 'rt' have to match")
## rt to halfWindowSize:
rt_step <- mean(diff(rt), na.rm = TRUE)
up_bound <- ceiling(peakwidth[2] / rt_step)
pk_idx <- which(MALDIquant:::.localMaxima(int, floor(peakwidth[1] /
rt_step)))
## First filter: int > noise
pk_idx <- pk_idx[int[pk_idx] >= noise]
if (!length(pk_idx))
return(matrix(ncol = 2, nrow = 0))
## Define the ROIs
scmin <- sapply(pk_idx - up_bound, max, y = 1)
scmax <- sapply(pk_idx + up_bound, min, y = int_len)
## Second filter: at least k values larger I
roi_idxs <- mapply(scmin, scmax, FUN = seq, SIMPLIFY = FALSE)
ok <- vapply(roi_idxs,
FUN = function(x, k, I) {
sum(int[x] >= I) >= k
},
FUN.VALUE = logical(1),
k = prefilter[1], I = prefilter[2],
USE.NAMES = FALSE)
if (any(ok))
cbind(scmin = scmin[ok], scmax = scmax[ok], sccent = pk_idx[ok])
else
matrix(ncol = 3, nrow = 0)
}
#' @description
#'
#' Simple helper function to narrow the identified chromatographic peak
#' boundaries excluding values that are below a certain threshold. This was
#' introduced to fix issue #300. Note: to be consistent with the original
#' code we *grow* the region on each side after subsetting.
#'
#' @param lm `integer(2)` with the lower and upper peak boundary.
#'
#' @param d `numeric` with the intensities (for baseline detection and wavelet
#' analysis).
#'
#' @param thresh `numeric(1)` defining the threshold below which values are
#' considered *zero*.
#'
#' @author Johannes Rainer
#'
#' @noRd
.narrow_rt_boundaries <- function(lm, d, thresh = 1) {
lm_seq <- lm[1]:lm[2]
above_thresh <- d[lm_seq] >= thresh
if (any(above_thresh)) {
## Expand by one on each side to be consistent with old code.
above_thresh <- above_thresh | c(above_thresh[-1], FALSE) |
c(FALSE, above_thresh[-length(above_thresh)])
lm <- range(lm_seq[above_thresh], na.rm = TRUE)
}
lm
}
Try the xcms package in your browser
Any scripts or data that you put into this service are public.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
Embedding an R snippet on your website
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.