expressopdnn {affypdnn}R Documentation

Position Dependant Nearest Neighbors model for affy


a wrapper to perform the PDNN method.


      # background correction
             bg.correct = FALSE,
             bgcorrect.method = NULL,
             bgcorrect.param = list(),
      # normalize
             normalize = FALSE,
             normalize.method = NULL,
             normalize.param = list(),
              pmcorrect.method = c("pdnn", "pdnnpredict"),
      # pdnn
             findparams.param = list(),          
      # expression values
             summary.subset = NULL,
      # PDNN expression values scaling
             eset.normalize = TRUE,
    = 500,
      # misc.
             verbose = TRUE,
             widget = FALSE)


abatch object of AffyBatch-class
bg.correct a boolean to express whether background correction is wanted or not.
bgcorrect.method the name of the background adjustment method
bgcorrect.param a list of parameters for bgcorrect.method (if needed/wanted)
eset An object of exprSet-class
normalize normalization step wished or not.
normalize.method the normalization method to use
normalize.param a list of parameters to be passed to the normalization method (if wanted).
pmcorrect.method the name of the PM adjustement method (only two choices here, default to 'pdnn').
findparams.param a list of parameters to be passed to find.params.pdnn
eset.normalize is any normalization step on expression values to be performed a value to scale against.
summary.subset a list of 'affyids'. If NULL, a expression summary value is computed for everything on the chip.
verbose logical value. If TRUE it writes out some messages.
widget a boolean to specify the use of widgets (the package tkWidget is required). NOTE: this not yet implemented !


expressopdnn is very similar to expresso. It is mainly a wrapper around the pre-processing steps `background correction', `normalization', `perfect match correction' and the PDNN method to compute expression values (see the first reference for more details about the preprocessing steps and and the second reference for further details about the PDNN method).

The wrapper expresso has no way to handle easily the computation of chip-wide results that have to be used during the computeExprSet step. An easy way to overcome this was to write this simple wrapper.

pdnn.scalevalue is performed after the expression values have computed to somehow `normalize' the values between different chips. When setting normalize to TRUE this step might be considered unnecessary (and the eset.normalize set to FALSE).


An object of exprsSet-class, with an attribute pps.warnings as returned by the method computeExprSet.

See Also

expresso and \code{computeExprVal.method.pdnn}


## load pre-computed parameters


## one CEL to go faster
afbatch <- Dilution[, 1]

## Take only few IDs (the 10 first)
ids <- ls(getCdfInfo(afbatch))[1:10]
eset <- expressopdnn(afbatch, bg.correct=FALSE,

[Package affypdnn version 1.1-0 Index]