gcrma.adjust.nomm: GCRMA pre-processing of arrays with custom CDF format

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

View source: R/gcrma.adjust.nomm.R

Description

gcrma.adjust.nomm is a wrapper function for functions in the gcrma package that allows to GCRMA-pre-process Affymetrix arrays with non-typical CDF package and layout (e.g. Affymetrix Exon arrays with custom CDF files). The function performs all steps of the GCRMA preprocessing: optical background correction, NSB background adjustment, quantile normalisation and RMA summarisation.

Usage

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gcrma.adjust.nomm(x, optical.correct = TRUE, verbose = TRUE,
affinity.spline.coefs, NCprobe, k = 0.5, GSB.adjust = TRUE, NC.pattern =
"bg", normalize.quantiles = TRUE, normalize.method="quantiles",
normalize.log2=FALSE, summarize = FALSE, summarize.method="rma", cl,
mc.cores, ret.residual.aggr=FALSE, residual.aggr.fun=function( z ){
mean( abs( z ) ) } )

Arguments

x

An AffyBatch object

optical.correct

If the data should be optical background adjusted.

verbose

Print progress information.

affinity.spline.coefs

The affinity spline coefficients for the GCRMA NSB adjustment. The package provides pre-calculated coefficients for human Exon arrays, that can be loaded with data( "affinity.spline.coefs.exon" ). Alternatively they can be calculated from the data using the base.profiles.nc or base.profiles from the gcrma package.

NCprobe

Indices of non-specific-background control probes within the PM data (not indices of probes in the matrix returned by the functions intensity or exprs, but indices of the probes in the intensity matrix returned by the pm function). The function tries to find NSB control probes within the data using a pattern search on the probe set ids defined in the CDF environment.

k

A tuning factor

GSB.adjust

If probe effects in specific binding should be adjusted.

NC.pattern

Pattern that is used to search for NCprobes in the CDF environment's probe set names.

normalize.quantiles

If the data should be quantiles normalised.

normalize.method

Which normalization method should be used. At the moment only quantiles normalization is implemented.

normalize.log2

Wheter the normalization should be performed in log2 or natural scale.

summarize

If the probe intensities should be summarised to probe set intensities (using the rma function/model). If FALSE an AffyBatch will be returned by the function with the background adjusted probe intensities.

summarize.method

The summarization method/function to be used. Either rma or plm for standard RMA summarization using the median polish algorithm or summarization with the fitPLM function from the affyPLM package.

cl

Optional paramter. A cluster object created by the makeCluster function from the snow package. If submitted a parallelized version of this function is used.

mc.cores

Optional paramter. Number of cores (CPUs) on which the background adjustment should be performed. Provides, similar to parameter cl, a significant speed-up of the calculation. Requires that the multicore/parallel package is installed.

ret.residual.aggr

Only for summarization using the fitPLM function (see parameter summarize.method above). Whether probe residual values should be aggregated per probe set. Note that if set to TRUE a ResExpressionSet will be returned with the aggregated residuals available in slot residuals.

residual.aggr.fun

A function that can be used to aggregate (combine/summarize) the probe residuals of a probe set.

Details

The function estimates the affinity spline coefficients using the expression intensities and sequences of the NSB background probes if affinity.spline.coefs is not submitted.

Value

An ExpressionSet with GCRMA preprocessed probe set intensities (if summarize=TRUE) or an AffyBatch object with GCRMA background adjusted probe intensity values (in natural scale). If ret.residual.aggr is set to TRUE a ResExpressionSet object is returned, that is essentially identical to an ExpressionSet, with an additional slot with a matrix (same dimensions than the expression matrix) of the aggregated probe residuals per probe set.

Author(s)

Johannes Rainer

References

Rainer J, Lelong J, Bindreither D, Mantinger C, Ploner C, Geley S, Kofler R. (2012) Research resource: transcriptional response to glucocorticoids in childhood acute lymphoblastic leukemia. Mol Endocrinol. 2012 Jan;26(1):178-93.

http://bioinfo.i-med.ac.at

See Also

gcrma.bkg.correct.matrix, gcrma.compute.affinities.local.pmonly


jotsetung/generalgcrma documentation built on May 19, 2019, 9:41 p.m.