plotBAF {CopyNumberPlots} | R Documentation

## plotBAF

### Description

Plot the B-allele frequency (BAF) data

### Usage

    plotBAF(karyoplot, snps, baf.column="baf", labels=NULL, points.cex=0.3, points.col="#333333", points.pch=16, label.cex=1.5, label.srt=90, label.margin=0.03, add.axis=TRUE, axis.cex=1.2, r0=0, r1=1, track.margin=0.1, data.panel=1, verbose=FALSE, ...)

### Arguments

`karyoplot` | (a KaryoPlot object) The object returned by the `plotKaryotype` function and representing the current active plot.
`snps` | (a GRanges, a list of GRanges or a GRangesList) An object with the positions of the SNPs and a column with the BAF values. Other columns are ignored. If it's a list of GRanges with different samples, all samples will be plotted, splitting the total plot space between them.
`baf.column` | (a character) The name of the column in `snps` with the BAF values. (defaults to "baf")
`labels` | (a character) The text of the label to identify the data. If NA, no label will be plotted. If NULL, if snps is a single sample GRanges it will default to "BAF", if it's a list of samples it will default to the names in the list or consecutive numbers if names(snps) is NULL. (defaults to NULL)
`points.cex` | (numeric) The size of the points. (defaults to 0.3)
`points.col` | (a color) The color of the points (defaults to "#333333")
`points.pch` | (numeric) The shape of the points. (defaults to 16, a filled circle)
`label.cex` | (numeric) The size of the label (defaults to 1.5)
`label.srt` | (numeric) The rotation of the label (defaults to 90, vertical text)
`label.margin` | (numeric) The margin between the label and the origin of the plot in plot coordinates (the width of the plot is 1). (defaults to 0.03)
`add.axis` | (logical) Whether to add an axis (defaults to TRUE)
`axis.cex` | (numeric) The size of the axis labels. (defaults to 1.2)
`r0` | (numeric) (karyoploteR parameter) r0 and r1 define the vertical range of the data panel to be used to draw this plot. They can be used to split the data panel in different vertical ranges (similar to tracks in a genome browser) to plot differents data. If NULL, they are set to the min and max of the data panel, it is, to use all the available space. (defaults to NULL)
`r1` | (numeric) (karyoploteR parameter) r0 and r1 define the vertical range of the data panel to be used to draw this plot. They can be used to split the data panel in different vertical ranges (similar to tracks in a genome browser) to plot differents data. If NULL, they are set to the min and max of the data panel, it is, to use all the available space. (defaults to NULL)
`track.margin` | (numeric) If snps is a list object, this is the margin between the samples BAF. (deafults to 0.1)
`data.panel` | (numeric) (karyoploteR parameter) The identifier of the data panel where the data is to be plotted. The available data panels depend on the plot type selected in the call to `plotKaryotype`. (defaults to 1)
`verbose` | (logical) Wether messages with information on the processing should be generated (defaults to FALSE)
`...` | The ellipsis operator can be used to specify any additional graphical parameters. Any additional parameter will be passed to the internal calls to karyoploteR functions.

### Details

This function plot the B-allele frequency (BAF) values on the genome. BAF values represent the frequency of one of the alleles (NOT always the minor allele) in the sample and usually come from SNP-array. However, it's possible to get similar values from NGS variant calling data (`loadSNPDataFromVCF` for example, will load a standard VCF and generate BAF-like values). The function plots the data points, an optional axis and an optional label identifying the data. The function expects a GRanges object with the position of the SNPs with a column (usually named 'baf') with the BAF values or any object valid to `toGRanges`. This object can be created with `loadSNPData`.

### Value

Invisibly returns the karyoplot object representing the plot. With it it is possible to add other elements to the plot using standrad karyoploteR functions

### Examples

    pos <- sort(floor(runif(1000, 1, 10000)))
    baf.data <- toGRanges("chr1", pos, pos)
    baf.data$baf <- rnorm(1000, mean = 0.5, sd = 0.05)
    baf.data$baf[1:400] <- baf.data$baf[1:400] + c(0.2, -0.2)

    kp <- plotKaryotype(zoom=toGRanges("chr1", 1, 10000))
    plotBAF(kp, baf.data)

    names(mcols(baf.data)) <- "values"
    kp <- plotKaryotype(zoom=toGRanges("chr1", 1, 10000))
    plotBAF(kp, baf.data, baf.column="values", r0=0, r1=0.5, points.col="red", labels="Values")
    plotBAF(kp, baf.data, baf.column=1, r0=0.5, r1=1, points.col="orange", labels="First", label.cex=0.8, points.cex=1.4)

    #Plotting a list
    baf.data2 <- baf.data
    baf.data2$baf <- rnorm(1000, mean = 0.5, sd = 0.05)
    baf.data$baf <- rnorm(1000, mean = 0.5, sd = 0.05)
    baf.data$baf[1:400] <- baf.data$baf[1:400] + c(0.2, -0.2)

    baf.list <- list(Tumor=baf.data, Normal=baf.data2)

    kp <- plotKaryotype(zoom=toGRanges("chr1", 1, 10000))
    plotBAF(kp, baf.list, labels=NULL)

    kp <- plotKaryotype(zoom=toGRanges("chr1", 1, 10000))
    plotBAF(kp, baf.list, labels=NULL, r1=0.8, label.cex=0.8, axis.cex=0.4)
    kpRect(kp, chr="chr1", x0=0, x1=pos[400], y0=0, y1=0.8, border="red")
    kpPlotNames(kp, chr="chr1", x0=0, x1=pos[400], y0=0, y1=0.8, labels = "Alteration", position = "top", col="red")

[Package CopyNumberPlots version 1.0.1 Index]