RmaBackgroundCorrection: The RmaBackgroundCorrection class

Description

Package: aroma.affymetrix Class RmaBackgroundCorrection Object ~~| ~~+--ParametersInterface ~~~~~~~| ~~~~~~~+--AromaTransform ~~~~~~~~~~~~| ~~~~~~~~~~~~+--Transform ~~~~~~~~~~~~~~~~~| ~~~~~~~~~~~~~~~~~+--ProbeLevelTransform ~~~~~~~~~~~~~~~~~~~~~~| ~~~~~~~~~~~~~~~~~~~~~~+--BackgroundCorrection ~~~~~~~~~~~~~~~~~~~~~~~~~~~| ~~~~~~~~~~~~~~~~~~~~~~~~~~~+--RmaBackgroundCorrection Directly known subclasses: public static class RmaBackgroundCorrection extends BackgroundCorrection This class represents the RMA background adjustment function.

Usage

RmaBackgroundCorrection(..., addJitter=FALSE, jitterSd=0.2)

Arguments

...

Arguments passed to the constructor of BackgroundCorrection.

addJitter

If TRUE, Zero-mean gaussian noise is added to the signals before being background corrected.

jitterSd

Standard deviation of the jitter noise added.

Fields and Methods

Methods: rll{ process Performs background correction. }

Methods inherited from BackgroundCorrection: getParameters, process

Methods inherited from ProbeLevelTransform: getRootPath

Methods inherited from Transform: getOutputDataSet, getOutputFiles

Methods inherited from AromaTransform: as.character, findFilesTodo, getAsteriskTags, getExpectedOutputFiles, getExpectedOutputFullnames, getFullName, getInputDataSet, getName, getOutputDataSet, getOutputDataSet0, getOutputFiles, getPath, getRootPath, getTags, isDone, process, setTags

Methods inherited from ParametersInterface: getParameterSets, getParameters, getParametersAsString

Methods inherited from Object: $, $<-, [[, [[<-, as.character, attach, attachLocally, clearCache, clearLookupCache, clone, detach, equals, extend, finalize, gc, getEnvironment, getFieldModifier, getFieldModifiers, getFields, getInstantiationTime, getStaticInstance, hasField, hashCode, ll, load, objectSize, print, save, asThis

Jitter noise

The fitting algorithm of the RMA background correction model may not converge if there too many small and discrete signals. To overcome this problem, a small amount of noise may be added to the signals before fitting the model. This is an ad hoc solution that seems to work. However, add Gaussian noise may generate non-positive signals.

Details

Internally bg.adjust is used to background correct the probe signals. The default is to background correct PM signals only.