Last data update: 2014.03.03

R: Plotting the PMD Segmentation
plotPMDSegmentationR Documentation

Plotting the PMD Segmentation

Description

This function generates a figure showing the PMD segmentation in a randomly chosen region.

Usage

plotPMDSegmentation(m, segs, numRegions = 1, pdfFilename=NULL, minCover = 5)

Arguments

m

GRanges object containing the methylation data.

segs

GRanges object containing the PMD segmentation. Return value of the segmentPMDs function (see example).

numRegions

The number of randomly chosen regions to be plotted. The default (1) can only be changed if a pdfFilename is provided (see below).

pdfFilename

Name of the pdf file in which the figure is saved. If no name is provided (default), the figure is printed to the screen.

minCover

Only CpGs with a coverage of at least minCover reads will be used for plotting.

Value

No return value. The function creates a figure showing the inferred segmentation for a randomly chosen region. The figure is either printed to the screen (default) or saved as a pdf if a filename is provided. If a filename (pdfFilename) is provided, several regions (set via the numRegions argument) can be plotted and saved in a multi-page pdf file. The randomly chosen region that is displayed is broken up into 6 panels and in each panel, the raw (ie unsmoothed) methylation levels of all CpGs with a minimal coverage of 5 reads are shown. PMDs are indicated as green bars, extending over the entire PMD.

Author(s)

Lukas Burger lukas.burger@fmi.ch

Examples


library(MethylSeekR)

# get chromosome lengths
library("BSgenome.Hsapiens.UCSC.hg18")
sLengths=seqlengths(Hsapiens)

# read methylation data
methFname <- system.file("extdata", "Lister2009_imr90_hg18_chr22.tab",
package="MethylSeekR")
meth.gr <- readMethylome(FileName=methFname, seqLengths=sLengths)

#segment PMDs
PMDsegments.gr <- segmentPMDs(m=meth.gr, chr.sel="chr22", seqLengths=sLengths)

#plot PMD segmentation examples
plotPMDSegmentation(m=meth.gr, segs=PMDsegments.gr, numRegions=1)


Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(MethylSeekR)
Loading required package: rtracklayer
Loading required package: GenomicRanges
Loading required package: BiocGenerics
Loading required package: parallel

Attaching package: 'BiocGenerics'

The following objects are masked from 'package:parallel':

    clusterApply, clusterApplyLB, clusterCall, clusterEvalQ,
    clusterExport, clusterMap, parApply, parCapply, parLapply,
    parLapplyLB, parRapply, parSapply, parSapplyLB

The following objects are masked from 'package:stats':

    IQR, mad, xtabs

The following objects are masked from 'package:base':

    Filter, Find, Map, Position, Reduce, anyDuplicated, append,
    as.data.frame, cbind, colnames, do.call, duplicated, eval, evalq,
    get, grep, grepl, intersect, is.unsorted, lapply, lengths, mapply,
    match, mget, order, paste, pmax, pmax.int, pmin, pmin.int, rank,
    rbind, rownames, sapply, setdiff, sort, table, tapply, union,
    unique, unsplit

Loading required package: S4Vectors
Loading required package: stats4

Attaching package: 'S4Vectors'

The following objects are masked from 'package:base':

    colMeans, colSums, expand.grid, rowMeans, rowSums

Loading required package: IRanges
Loading required package: GenomeInfoDb
Loading required package: mhsmm
Loading required package: mvtnorm
> png(filename="/home/ddbj/snapshot/RGM3/R_BC/result/MethylSeekR/plotPMDSegmentation.Rd_%03d_medium.png", width=480, height=480)
> ### Name: plotPMDSegmentation
> ### Title: Plotting the PMD Segmentation
> ### Aliases: plotPMDSegmentation
> 
> ### ** Examples
> 
> 
> library(MethylSeekR)
> 
> # get chromosome lengths
> library("BSgenome.Hsapiens.UCSC.hg18")
Loading required package: BSgenome
Loading required package: Biostrings
Loading required package: XVector
> sLengths=seqlengths(Hsapiens)
> 
> # read methylation data
> methFname <- system.file("extdata", "Lister2009_imr90_hg18_chr22.tab",
+ package="MethylSeekR")
> meth.gr <- readMethylome(FileName=methFname, seqLengths=sLengths)
reading methylome data
Read 200000 records
> 
> #segment PMDs
> PMDsegments.gr <- segmentPMDs(m=meth.gr, chr.sel="chr22", seqLengths=sLengths)
training PMD-HMM on chromosome chr22
performing viterbi segmentation
creating GRanges object
> 
> #plot PMD segmentation examples
> plotPMDSegmentation(m=meth.gr, segs=PMDsegments.gr, numRegions=1)
> 
> 
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>