preprocessedLoader {macat}R Documentation

Read in data and produce MACAT list

Description

This function reads expression data either from a saved R-file (.RData,.rda), or from a tab-separated text-file (.xls). For building a MACAT-list structure from objects in your workspace, you can either use this function or the convenience wrapper 'buildMACAT'.

Usage

preprocessedLoader(rdatafile, chip, labels = NULL, chromLocObj = NULL,
rdafile = TRUE, tabfile = FALSE, labelfile = FALSE)

Arguments

rdatafile Complete name of the expression data file, or the expression matrix
chip Identifier of the used microarray. To date only commercial Affymetrix microarrays are supported by MACAT
labels Classlabels of the samples, vector of same length as number of columns in expression matrix; alternatively complete name of textfile with one label per line
chromLocObj Object of class chromLocation specifying the genomic position, each probe on the array is mapped to. If not provided, it is build in the function using annotate's function buildChromLocation.
rdafile Logical; is first argument a saved R-file?
tabfile Logical; is first argument a tab-separated text file?
labelfile Logical; is third argument a file with one label per line?

Value

List of class 'MACATData' with 6 components:

geneName Identifiers of genes/probe sets in expression data
geneLocation Location of genes on their chromosome as distance from 5'end in base pairs Negative numbers denote genes on the antisense strand.
chromosome Chromosome of the respective gene. Components 'geneName', 'geneLocation', and 'chromosome' are in the same order.
expr expression matrix with rows = genes and columns = samples/patients
labels (disease) subtype of each sample, has length = number of columns of expression matrix
chip Identifier for Microarray used for the experiments

Note

At present, macat can only work with Affymetrix microarrays, for which an annotation package is installed on your system. Such annotation packages can either be obtained from the Bioconductor annotation packages repository or be constructed using the Bioconductor package AnnBuilder. For an example, see the common annotation package hgu95av2.

Author(s)

MACAT development team

See Also

buildMACAT,read.table,stjd,stjude in package 'stjudem'

Examples

 ## Not run: 
  # assume you have your HG-U95Av2 expression values in a
  # tab-separated text file, called 'foo.txt'
  mydata <- preprocessedLoader("foo.txt","hgu95av2",rdafile=FALSE,tabfile=TRUE)
 
## End(Not run)

[Package macat version 1.16.0 Index]