updateCel: Updates a CEL file

In affxparser: Affymetrix File Parsing SDK

Description

Updates a CEL file.

Usage

updateCel(filename, indices=NULL, intensities=NULL, stdvs=NULL, pixels=NULL,
  writeMap=NULL, ..., verbose=0)

Arguments

filename	The filename of the CEL file.
indices	A numeric vector of cell (probe) indices specifying which cells to updated. If NULL, all indices are considered.
intensities	A numeric vector of intensity values to be stored. Alternatively, it can also be a named data.frame or matrix (or list) where the named columns (elements) are the fields to be updated.
stdvs	A optional numeric vector.
pixels	A optional numeric vector.
writeMap	An optional write map.
...	Not used.
verbose	An integer specifying how much verbose details are outputted.

Details

Currently only binary (v4) CEL files are supported. The current version of the method does not make use of the Fusion SDK, but its own code to navigate and update the CEL file.

Value

Returns (invisibly) the pathname of the file updated.

Author(s)

Henrik Bengtsson

Examples

##############################################################
if (require("AffymetrixDataTestFiles")) {            # START #
##############################################################

# Search for some available Calvin CEL files
path <- system.file("rawData", package="AffymetrixDataTestFiles")
files <- findFiles(pattern="[.](cel|CEL)$", path=path, recursive=TRUE, firstOnly=FALSE)
files <- grep("FusionSDK_HG-U133A", files, value=TRUE)
files <- grep("Calvin", files, value=TRUE)
file <- files[1]

# Convert to an XDA CEL file
filename <- file.path(tempdir(), basename(file))
if (file.exists(filename))
  file.remove(filename)
convertCel(file, filename)


fields <- c("intensities", "stdvs", "pixels")

# Cells to be updated
idxs <- 1:2

# Get CEL header
hdr <- readCelHeader(filename)

# Get the original data
cel <- readCel(filename, indices=idxs, readStdvs=TRUE, readPixels=TRUE)
print(cel[fields])
cel0 <- cel

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Square-root the intensities
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
updateCel(filename, indices=idxs, intensities=sqrt(cel$intensities))
cel <- readCel(filename, indices=idxs, readStdvs=TRUE, readPixels=TRUE)
print(cel[fields])


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Update a few cell values by a data frame
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
data <- data.frame(
  intensities=cel0$intensities,
  stdvs=c(201.1, 3086.1)+0.5,
  pixels=c(9,9+1)
)
updateCel(filename, indices=idxs, data)

# Assert correctness of update
cel <- readCel(filename, indices=idxs, readStdvs=TRUE, readPixels=TRUE)
print(cel[fields])
for (ff in fields) {
  stopifnot(all.equal(cel[[ff]], data[[ff]], .Machine$double.eps^0.25))
}

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Update a region of the CEL file
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Load pre-defined data
side <- 306
pathname <- system.file("extras/easternEgg.gz", package="affxparser")
con <- gzfile(pathname, open="rb")
z <- readBin(con=con, what="integer", size=1, signed=FALSE, n=side^2)
close(con)
z <- matrix(z, nrow=side)
side <- min(hdr$cols - 2*22, side)
z <- as.double(z[1:side,1:side])
x <- matrix(22+0:(side-1), nrow=side, ncol=side, byrow=TRUE)
idxs <- as.vector((1 + x) + hdr$cols*t(x))
# Load current data in the same region
z0 <- readCel(filename, indices=idxs)$intensities
# Mix the two data sets
z <- (0.3*z^2 + 0.7*z0)
# Update the CEL file
updateCel(filename, indices=idxs, intensities=z)

# Make some spatial changes
rotate270 <- function(x, ...) {
  x <- t(x)
  nc <- ncol(x)
  if (nc < 2) return(x)
  x[,nc:1,drop=FALSE]
}

# Display a spatial image of the updated CEL file
cel <- readCelRectangle(filename, xrange=c(0,350), yrange=c(0,350))
z <- rotate270(cel$intensities)
sub <- paste("Chip type:", cel$header$chiptype)
image(z, col=gray.colors(256), axes=FALSE, main=basename(filename), sub=sub)
text(x=0, y=1, labels="(0,0)", adj=c(0,-0.7), cex=0.8, xpd=TRUE)
text(x=1, y=0, labels="(350,350)", adj=c(1,1.2), cex=0.8, xpd=TRUE)


# Clean up
file.remove(filename)
rm(files, cel, cel0, idxs, data, ff, fields, rotate270)


##############################################################
}                                                     # STOP #
##############################################################

affxparser documentation built on Nov. 8, 2020, 7:26 p.m.