PeakErrorChrom <- function
### Compute the PeakError assuming that peaks and regions are on the
### same chrom.
(peaks,
### data.frame with columns chromStart, chromEnd. NOTE: chromStart
### should be 0-based and chromEnd should be 1-based. EXAMPLE: the
### first 100 base of of a chromosome are chromStart=0,
### chromEnd=100. The second 100 bases are chromStart=100,
### chromEnd=200.
regions
### data.frame with columns chromStart, chromEnd.
){
checkPositions(peaks)
checkPositions(regions)
p <- peaks[order(peaks$chromStart), ]
r <- regions[order(regions$chromStart), ]
if(is.null(r$annotation)){
stop("need annotation column in regions")
}
ann2code <- c(noPeaks=0, peakStart=1, peakEnd=2, peaks=3)
code <- ann2code[as.character(r$annotation)]
unknown <- r$annotation[is.na(code)]
if(length(unknown)){
u <- paste(unique(unknown), collapse=", ")
stop("unknown annotation (", u,
") annotations must be one of: ",
paste(names(ann2code), collapse=", "))
}
result <-
.C("PeakError_interface",
peak.chromStart=as.integer(p$chromStart),
peak.chromEnd=as.integer(p$chromEnd),
peak.count=as.integer(nrow(p)),
chromStart=as.integer(r$chromStart),
chromEnd=as.integer(r$chromEnd),
annotation=as.integer(code),
region.count=as.integer(nrow(r)),
tp=integer(nrow(r)),
fp=integer(nrow(r)),
possible.tp=integer(nrow(r)),
possible.fp=integer(nrow(r)),
PACKAGE="PeakError")
err <- with(result, {
data.frame(chromStart, chromEnd, annotation=r$annotation,
tp, possible.tp, fp, possible.fp)
})
err$fp.status <- ifelse(err$fp, "false positive", "correct")
err$fn <- with(err, possible.tp-tp)
err$fn.status <- ifelse(err$fn, "false negative", "correct")
err$status <- with(err, ifelse(fn, "false negative",
ifelse(fp, "false positive", "correct")))
err
### data.frame with 1 row for each region and error columns.
}
PeakError <- structure(function
### Compute true and false positive peak calls, with respect to a
### database of annotated regions.
(peaks,
### data.frame with columns chrom, chromStart, chromEnd. NOTE:
### chromStart should be 0-based and chromEnd should be
### 1-based. EXAMPLE: the first 100 base of of a chromosome are
### chromStart=0, chromEnd=100. The second 100 bases are
### chromStart=100, chromEnd=200.
regions
### data.frame with columns chrom, chromStart, chromEnd, annotation.
){
checkChrom(peaks)
checkChrom(regions)
peak.list <- split(peaks, peaks$chrom)
region.list <- split(regions, regions$chrom, drop=TRUE)
error.list <- list()
for(chrom in names(region.list)){
p <- peak.list[[chrom]]
if(is.null(p)){
p <- data.frame(chromStart=integer(), chromEnd=integer())
}
r <- region.list[[chrom]]
result <- PeakErrorChrom(p, r)
error.list[[chrom]] <- data.frame(chrom, result)
}
err <- do.call(rbind, error.list)
rownames(err) <- NULL
err
### data.frame for each region with additional counts of true
### positives (tp, possible.tp), false positives (fp, possible.fp,
### fp.status), and false negatives (fn, fn.status).
}, ex=function(){
x <- seq(5, 85, by=5)
peaks <- rbind(
Peaks("chr2", x, x+3),
Peaks("chr3", c(25, 38, 57), c(33, 54, 75)),
Peaks("chr4", c(5, 32, 38, 65), c(15, 35, 55, 85)),
Peaks("chr5", c(12, 26, 56, 75), c(16, 54, 59, 85)))
regions.list <- list()
for(chr in 1:5){
regions.list[[chr]] <- data.frame(
chrom=paste0("chr", chr),
chromStart=c(10, 30, 50, 70),
chromEnd=c(20, 40, 60, 80),
annotation=c("noPeaks", "peakStart", "peakEnd", "peaks"))
}
regions <- do.call(rbind, regions.list)
err <- PeakError(peaks, regions)
ann.colors <- c(
noPeaks="#f6f4bf",
peakStart="#ffafaf",
peakEnd="#ff4c4c",
peaks="#a445ee")
if(require(ggplot2)){
ggplot()+
geom_rect(aes(
xmin=chromStart+1/2, xmax=chromEnd+1/2,
ymin=-1, ymax=1,
fill=annotation,
linetype=fn.status,
size=fp.status),
data=err, color="black")+
scale_y_continuous("", breaks=NULL)+
scale_linetype_manual(
values=c("false negative"="dotted", correct="solid"))+
scale_size_manual(
values=c("false positive"=3, correct=1))+
scale_fill_manual(
values=ann.colors,
breaks=names(ann.colors))+
facet_grid(chrom ~ .)+
theme_bw()+
guides(
fill=guide_legend(order=1),
linetype=guide_legend(order=2, override.aes=list(fill="white")),
size=guide_legend(order=3, override.aes=list(fill="white")))+
theme(panel.margin=grid::unit(0, "cm"))+
geom_segment(aes(
chromStart+1/2, 1/2, xend=chromEnd+1/2, yend=1/2),
data=peaks, color="deepskyblue", size=2)+
scale_x_continuous(
"position on chromosome",
breaks=seq(10, 90, by=10))+
geom_text(aes(
base, -1/2, label="N"),
data.frame(base=10:90),
color="deepskyblue")
}
})
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