ASEset-class {AllelicImbalance} | R Documentation

## ASEset objects

### Description

Object that holds allele counts, genomic positions and map-bias for a set of SNPs

### Usage

    alleleCounts(x, strand = "*", return.class = "list")

    ## S4 method for signature 'ASEset'
    alleleCounts(x, strand = "*", return.class = "list")

    alleleCounts(x, ...) <- value

    ## S4 replacement method for signature 'ASEset'
    alleleCounts(x, strand = "*", return.class = "array",
      ...) <- value

    mapBias(x, ...)

    ## S4 method for signature 'ASEset'
    mapBias(x, return.class = "list")

    fraction(x, ...)

    ## S4 method for signature 'ASEset'
    fraction(x, strand = "*",
      top.fraction.criteria = "maxcount", verbose = FALSE, ...)

    arank(x, return.type = "names", return.class = "list", strand = "*", ...)

    frequency(x, ...)

    genotype(x, ...)

    ## S4 method for signature 'ASEset'
    genotype(x, return.class = "matrix")

    genotype(x) <- value

    ## S4 replacement method for signature 'ASEset'
    genotype(x) <- value

    countsPerSnp(x, ...)

    ## S4 method for signature 'ASEset'
    countsPerSnp(x, return.class = "matrix",
      return.type = "mean", strand = "*")

    countsPerSample(x, ...)

    ## S4 method for signature 'ASEset'
    countsPerSample(x, return.class = "matrix",
      return.type = "mean", strand = "*")

    phase(x, ...)

    ## S4 method for signature 'ASEset'
    phase(x, return.class = "matrix")

    phase(x) <- value

    ## S4 replacement method for signature 'ASEset'
    phase(x) <- value

    mapBias(x) <- value

    ## S4 replacement method for signature 'ASEset'
    mapBias(x) <- value

    refExist(x)

    ## S4 method for signature 'ASEset'
    refExist(x)

    ref(x)

    ## S4 method for signature 'ASEset'
    ref(x)

    ref(x) <- value

    ## S4 replacement method for signature 'ASEset,ANY'
    ref(x) <- value

    altExist(x)

    ## S4 method for signature 'ASEset'
    altExist(x)

    alt(x)

    ## S4 method for signature 'ASEset'
    alt(x)

    alt(x) <- value

    ## S4 replacement method for signature 'ASEset,ANY'
    alt(x) <- value

    aquals(x, ...)

    ## S4 method for signature 'ASEset'
    aquals(x)

    aquals(x) <- value

    ## S4 replacement method for signature 'ASEset'
    aquals(x) <- value

    maternalAllele(x, ...)

    ## S4 method for signature 'ASEset'
    maternalAllele(x)

    paternalAllele(x, ...)

    ## S4 method for signature 'ASEset'
    paternalAllele(x)

### Arguments

`x` | ASEset object
`strand` | which strand of '+', '-' or '*'
`return.class` | return 'list' or 'array'
`...` | additional arguments
`value` | replacement variable
`top.fraction.criteria` | 'maxcount', 'ref' or 'phase'
`verbose` | makes function more talkative
`return.type` | return 'names', rank or 'counts'

### Details

An ASEset object differs from a regular RangedSummarizedExperiment object in that the assays contains an array instead of matrix. This array has ranges on the rows, sampleNames on the columns and variants in the third dimension.

It is possible to use the commands barplot and locationplot on an ASEset object see more details in `barplot` and `locationplot`.

Three different alleleCount options are available. The simples one is the * option, and is for experiments where the strand information is not known e.g. non-stranded data. The unknown strand could also be for strand specific data when the aligner could not find any strand associated with the read, but this should normally not happen, and if it does probably having an extremely low mapping quality. Then there are an option too add plus and minus stranded data. When using this, it is essential to make sure that the RNA-seq experiment under analysis has in fact been created so that correct strand information was obtained. The most functions will by default have their strand argument set to '*'.

The phase information is stored by the convention of 'maternal chromosome|paternal chromosome', with 0 as reference allele and 1 as alternative allele. '|' when the phase is known and '/' when the phase is unknown. Internally the information will be stored as an three dimensional array, dim 1 for SNPs, dim 2 for Samples and dim 3 which is fixed and stores maternal chromosome, paternal chromosome and phased (1 equals TRUE).

### Value

An object of class ASEset containing location information and allele counts for a number of SNPs measured in a number of samples on various strand, as well as mapBias information. All data is stored in a manner similar to the SummarizedExperiment class.

### Table

table(...)

Arguments:

...

  An `ASEset object` that contains the variants of interest

The generics for table does not easily allow more than one argument so in respect to the different strand options, `table` will return a SimpleList with length 3, one element for each strand.

### Frequency

frequency(x, return.class = "list", strand = "*", threshold.count.sample = 15)

Arguments:

x

  An `ASEset object` that contains the variants of interest

x

  threshold.count.samples

if sample has fewer counts the function return NA.

### Constructor

ASEsetFromCountList(rowRanges, countListNonStranded = NULL, countListPlus = NULL, countListMinus = NULL, countListUnknown = NULL, colData = NULL, mapBiasExpMean = array(), verbose=FALSE, ...)

Arguments:

rowRanges

  A `GenomicRanges object` that contains the variants of interest

countListNonStranded

  A `list` where each entry is a matrix with allele counts as columns and sample counts as rows

countListPlus

  A `list` where each entry is a matrix with allele counts as columns and sample counts as rows

countListMinus

  A `list` where each entry is a matrix with allele counts as columns and sample counts as rows

countListUnknown

  A `list` where each entry is a matrix with allele counts as columns and sample counts as rows

colData

  A `DataFrame` object containing sample specific data

mapBiasExpMean

  A 3D `array` describing mapping bias. The SNPs are in the 1st dimension, samples in the 2nd dimension and variants in the 3rd dimension.

verbose

  Makes function more talkative

...

  arguments passed on to SummarizedExperiment constructor

### Author(s)

Jesper R. Gadin, Lasse Folkersen

### Examples

    #make example countList
    set.seed(42)
    countListPlus <- list()
    snps <- c('snp1','snp2','snp3','snp4','snp5')
    for(snp in snps){
      count<-matrix(rep(0,16),ncol=4,dimnames=list(
    c('sample1','sample2','sample3','sample4'),
    c('A','T','G','C')))
      #insert random counts in two of the alleles
      for(allele in sample(c('A','T','G','C'),2)){
    count[,allele]<-as.integer(rnorm(4,mean=50,sd=10))
      }
      countListPlus[[snp]] <- count
    }

    #make example rowRanges
    rowRanges <- GRanges(
      seqnames = Rle(c('chr1', 'chr2', 'chr1', 'chr3', 'chr1')),
      ranges = IRanges(1:5, width = 1, names = head(letters,5)),
      snp = paste('snp',1:5,sep='')
    )

    #make example colData
    colData <- DataFrame(Treatment=c('ChIP', 'Input','Input','ChIP'),
     row.names=c('ind1','ind2','ind3','ind4'))

    #make ASEset
    a <- ASEsetFromCountList(rowRanges, countListPlus=countListPlus,
    colData=colData)

    #example phase matrix (simple form)
    p1 <- matrix(sample(c(1,0),replace=TRUE, size=nrow(a)*ncol(a)),nrow=nrow(a), ncol(a))
    p2 <- matrix(sample(c(1,0),replace=TRUE, size=nrow(a)*ncol(a)),nrow=nrow(a), ncol(a))
    p <- matrix(paste(p1,sample(c("|","|","/"), size=nrow(a)*ncol(a), replace=TRUE), p2, sep=""),
    	nrow=nrow(a), ncol(a))

    phase(a) <- p

    #generate ASEset from array
    snps <- 999
    samples <-5
    ar <-array(rep(unlist(lapply(1:snps,
    			function(x){(sample(c(TRUE,FALSE,TRUE,FALSE), size = 4))})), samples),
    			dim=c(4,snps,samples))
    ar2 <- array(sample(50:300, 4*snps*samples,replace=TRUE), dim=c(4,snps,samples))
    ar2[ar] <- 0
    ar2 <- aperm(ar2, c(2, 3, 1))
    dimnames(ar2) <- list(paste("snp",1:snps,sep=""),paste("sample",1:samples,sep=""),
    						c("A","C","G","T"))
    gr <- GRanges(seqnames=c("chr2"), ranges=IRanges(start=1:dim(ar2)[1], width=1), strand="*")
    a <- ASEsetFromArrays(gr, countsUnknown=ar2)

[Package AllelicImbalance version 1.20.0 Index]