read.ilmn: Read Illumina Expression Data

Description Usage Arguments Details Value Author(s) See Also Examples

Description

Read Illumina summary probe profile files and summary control probe profile files

Usage

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read.ilmn(files=NULL, ctrlfiles=NULL, path=NULL, ctrlpath=NULL,
probeid="Probe",  annotation=c("TargetID", "SYMBOL"), expr="AVG_Signal", other.columns="Detection", 
sep="\t", quote="\"", verbose=TRUE, ...)

Arguments

files

character vector giving the names of the summary probe profile files.

ctrlfiles

character vector giving the names of the summary control probe profile files.

path

character string giving the directory containing the summary probe profile files. The default is the current working directory.

ctrlpath

character string giving the directory containing the summary control probe profile files. Defaults to the same directory as for the probe profile files.

probeid

character string giving the name of the probe identifier column.

annotation

character vector giving possible names of the annotation column. It could be called "TargetID" or "SYMBOL" depending on which version of BeadStudio is used.

expr

character string giving the keyword in the names of the expression intensity columns.

other.columns

character vector giving the keywords in the names of extra columns required, such as "Detection", "Avg_NBEADS", "BEAD_STDEV" etc. Each keyword corresponds to one type of columns. The detection p value columns will be read in by default.

sep

the field separator character.

quote

character string of characters to be treated as quote marks.

verbose

logical, TRUE to report names of profile files being read.

...

any other parameters are passed on to read.columns.

Details

Illumina BeadStudio ouputs probe intensities (regular probe intensities) and control probe intensities to summary probe profile files (containing regular probes) and summary control probe profile files, respectively. If both files and ctrlfiles are not NULL, this function will combine the data read from the two file types and save them to an EListRaw-class object. If one of them is NULL, then only the required data are read in.

Probe types are indicated in the Status column of genes, a component of the returned EListRaw-class object. There are totally seven types of control probes including negative, biotin, labeling, cy3_hyb, housekeeping, high_stringency_hyb or low_stringency_hyb. Regular probes have the probe type regular. The Status column will not be created if ctrlfiles is NULL.

To read in columns other than probeid, annotation and expr, users needs to specify keywords in other.columns. One keyword corresponds to one type of columns. Examples of keywords are "Detection", "Avg_NBEADS", "BEAD_STDEV" etc.

Value

An EListRaw-class object with the following components:

E

numeric matrix of raw intensities.

genes

data.frame of probe annotation.

targets

data.frame of sample information.

other

list of other column data.

Author(s)

Wei Shi and Gordon K Smyth

See Also

read.ilmn.targets reads in Illumina expression data using the file information extracted from a target data frame which is often created by the readTargets function.

neqc performs normexp by control background correction, log transformation and quantile between-array normalization for Illumina expression data.

normexp.fit.control estimates the parameters of the normal+exponential convolution model with the help of negative control probes.

propexpr estimates the proportion of expressed probes in a microarray.

Examples

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## Not run: 
x <- read.ilmn(files="sample probe profile.txt",
               ctrlfiles="control probe profile.txt")

## End(Not run)
# See neqc and beadCountWeights for other examples using read.ilmn

richierocks/limma2 documentation built on May 27, 2019, 8:47 a.m.