AffyBatch-class {affy} | R Documentation

## Class AffyBatch

### Description

This is a class representation for Affymetrix GeneChip probe level data. The main component are the intensities from multiple arrays of the same `CDF` type. In extends `exprSet-class`.

### Objects from the Class

Objects can be created using the function `read.affybatch` or the wrapper `ReadAffy`.

### Slots

`cdfName`:
  Object of class `"character"` representing the name of `CDF` file associated with the arrays in the `AffyBatch`.
`nrow`:
  Object of class `"numeric"` representing the physical number of rows in the arrays.
`ncol`:
  Object of class `"numeric"` representing the physical number of columns in the arrays.
`exprs`:
  Object of class "matrix" inherited from `exprSet`. The matrix contains one probe per row and one chip per column.
`se.exprs`:
  Object of class "matrix" inherited from `exprSet`.
`phenoData`:
  Object of class "phenoData" inherited from `exprSet`.
`annotation`
  A character string identifying the annotation that may be used for the `exprSet` instance.
`description`:
  Object of class "MIAME". For compatibility with previous version of this class description can also be a "character". The class `characterOrMIAME` has been defined just for this.
`notes`:
  Object of class "character" Vector of explanatory text

### Extends

Class `"exprSet"`, directly.

### Methods

cdfName
  `signature(object = "AffyBatch")`: Obtains the cdfName slot.
pm<-
  `signature(object = "AffyBatch")`: replaces the perfect match intensities
pm
  `signature(object = "AffyBatch")`: extracts the pm intensities.
mm<-
  `signature(object = "AffyBatch")`: replaces the mismatch intensities.
mm
  `signature(object = "AffyBatch")`: extracts the mm intensities.
probes
  `signature(object = "AffyBatch", which)`: extract the perfect match or mismatch probe intensities. Uses which can be "pm" and "mm".
[<-
  `signature(x = "AffyBatch")`: replaces subsets.
[
  `signature(x = "AffyBatch")`: subsets by array.
[[
  `signature(x = "AffyBatch")`: extracts each array as an `Cel` instance.
boxplot
  `signature(x = "AffyBatch")`: creates a `boxplots of log base 2 intensities.`
hist
  `signature(x = "AffyBatch")`: creates a plot showing all the histograms of the pm,mm or both data. See `plot.density`
computeExprSet
  `signature(x = "AffyBatch", summary.method = "character")`: For each probe set computes an expression value using `summary.method`.
geneNames
  `signature(object = "AffyBatch")`: return the probe set names also referred to as the Affymetrix IDs.
getCdfInfo
  `signature(object = "AffyBatch")`: retrieve the environment that defines the location of probes by probe set.
image
  `signature(x = "AffyBatch")`: creates an image for each sample.
indexProbes
  `signature(object = "AffyBatch", which = "character")`: returns a list with locations of the probes in each probe set. The affyID corresponding to the probe set to retrieve can be specified in an optional parameter `genenames`. By default, all the affyIDs are retrieved. The names of the elements in the list returned are the affyIDs. `which` can be "pm", "mm", or "both". If "both" then perfect match locations are given followed by mismatch locations.
intensity<-
  `signature(object = "AffyBatch")`: a replacement method for the `exprs` slot, i.e. the intensities.
intensity
  `signature(object = "AffyBatch")`: extract the `exprs` slot, i.e. the intensities.
length
  `signature(x = "AffyBatch")`: returns the number of samples.
pmindex
  `signature(object = "AffyBatch")`: return the location of perfect matches in the intensity matrix.
mmindex
  `signature(object = "AffyBatch")`: return the location of the mismatch intensities.
ncol
  `signature(x = "AffyBatch")`: An accessor function for `ncol`.
nrow
  `signature(x = "AffyBatch")`: an accessor function for `nrow`
.
normalize
  `signature(object = "AffyBatch")`: a method to `normalize`. The method accepts an argument `method`. The default methods is specified in package options (see the main vignette).
normalize.methods
  `signature(object = "AffyBatch")`: returns the normalization methods defined for this class. See `normalize`.
probeNames
  `signature(object = "AffyBatch")`: returns the probe set associated with each row of the intensity matrix.
probeset
  `signature(object = "AffyBatch",genenames=NULL, locations=NULL)`: Extracts `ProbeSet` objects related to the probe sets given in genenames. If an alternative set of locations defining pms and mms a list with those locations should be passed via the `locations` argument.
bg.correct
  `signature(object = "AffyBatch", method="character")`
applies background correction methods defined by method.

### Note

This class is better described in the vignette.

### See Also

related methods `merge.AffyBatch`, `split.AffyBatch` and `pairs.AffyBatch`, and related classes `Cel`, `Cdf` and `exprSet-class`

### Examples

    ## load example
    data(affybatch.example)

    ## nice print
    print(affybatch.example)

    pm(affybatch.example)[1:5,]
    mm(affybatch.example)[1:5,]

    ## get indexes for the PM probes for the affyID "A28102_at"
    mypmindex <- pmindex(affybatch.example,"A28102_at")
    ## same operation using the primitive
    mypmindex <- indexProbes(affybatch.example, which="pm", genenames="A28102_at")[[1]]
    ## get the probe intensities from the index
    intensity(affybatch.example)[mypmindex, ]

    ## load bigger example (try 'help(Dilution)' )
    data(affybatch.example)
    description(affybatch.example) ##we can also use the methods of exprSet
    sampleNames(affybatch.example)
    abstract(affybatch.example)

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