Btw, just a few days ago in BSgenome devel I added a coercion method from GenomeData to RangedData, ie: myGenomeData <- GenomeData(list(chr10 = Rle(1:1000, 1:1000), chr11 = Rle(1:100, 100:1))) myRangedData <- as(myGenomeData, "RangedData") export(myRangedData, "mytrack.wig") Would work. On Thu, Jun 4, 2009 at 4:30 PM, Patrick Aboyoun <paboyoun@fhcrc.org> wrote: > Simon, > Below is code that achieves what I think you are after. I'll have to ask > Michael if there is a cleaner way, and if there isn't we should create one. > > Also I know the classes can be a bit bewildering and here is some > information that may help you out. Both a RangedData object and a GenomeData > object represent a list across spaces that (may or may not in the case of > RangedData) represent chromosomes. A RangedData object is more rigid and > requires you to have ranges within each of the spaces with possibly an > associated rectangular data set. A GenomeData object is essentially a list > where the elements represents unstructured information on the chromosomes > (i.e. the elements can contain whatever you want them too). They relate to > Rle objects in the following manner: an Rle object can produce a RangedData > object of length 1 and a GenomeData object of length k containing Rle > objects as elements can produce a RangedData object of length k. > > I hoped that helped. > > > Patrick > > > > ##################################################### > > suppressMessages(library(IRanges)) > suppressMessages(library(rtracklayer)) > suppressMessages(library(BSgenome)) > > myGenomeData <- GenomeData(list(chr10 = Rle(1:1000, 1:1000), chr11 = > Rle(1:100, 100:1))) > myRangedData <- do.call(c, lapply(as.list(myGenomeData), as, "RangedData")) > export(myRangedData, "mytrack.wig", format = "wig") > > > myRangedData > RangedData: 1100 ranges by 1 columns > columns(1): score > sequences(2): chr10 chr11 > > > sessionInfo() > R version 2.9.0 (2009-04-17) > x86_64-unknown-linux-gnu > > locale: > > LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;LC_COLLATE=en_ US.UTF-8;LC_MONETARY=C;LC_MESSAGES=en_US.UTF-8;LC_PAPER=en_US.UTF-8;LC _NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-8;LC_IDEN TIFICATION=C > > attached base packages: > [1] stats graphics grDevices utils datasets methods base > other attached packages: > [1] BSgenome_1.12.2 Biostrings_2.12.5 rtracklayer_1.4.0 RCurl_0.97-3 > [5] bitops_1.0-4.1 IRanges_1.2.2 > loaded via a namespace (and not attached): > [1] Biobase_2.4.1 XML_2.5-0 > > Simon Anders wrote: > >> Dear Patrick, Hervé, Michael or Martin >> >> I'm unclear on how to get from an IRanges Rle object to a RangedData >> object to use with rtracklayer's export function. >> >> The use case is as follows: >> >> Let's say I caclulate a coverage vector from some ChIP-Seq data, e.g.: >> >> library(IRanges) >> library(ShortRead) >> library(rtracklayer) >> library(BSgenome.Mmusculus.UCSC.mm9) >> >> # Load the example data from the ChIP-Seq tutorial >> load("ctcf.rda") >> >> # Calculate the coverage >> cvg = coverage( ctcf, width = seqlengths( Mmusculus ) ) >> >> Then, I get a GenomeData object that contains Rle objects: >> >> > cvg >> A GenomeData instance >> chromosomes(3): chr10 chr11 chr12 >> > cvg$chr10 >> 'integer' Rle instance of length 129987043 with 308238 runs >> Lengths: 24 968 5 3 11 5 3 2 2 2 ... >> Values : 1 0 1 2 3 4 3 4 3 4 ... >> >> Given that coverage data is a very typical case of something that one >> would like to display as a track in a genome browser, it would be nice if >> the rtracklayer object could deal with it. For example I might want to >> export the 'cvg' object as a wiggle file with rtracklayer's 'export' >> function or add it to a browser session with the 'track<-' function. >> >> However, 'export' cannot deal with it >> >> > export( cvg, "wig" ) >> Error in function (classes, fdef, mtable) : >> unable to find an inherited method for function "export.ucsc", for >> signature "GenomeData" >> > export( cvg$chr10, "wig" ) >> Error in function (classes, fdef, mtable) : >> unable to find an inherited method for function "export.ucsc", for >> signature "Rle" >> >> It seems that it expects a RangedData object, or, alternatively, a >> RangedDataList. >> >> It seems to me that there should be a one-to-one correspondance from Rle >> to RangedData and from GenomeData to RangedDataList. How can I convert from >> one to the other? And why are there both kinds of classes? >> >> Thanks in advance. >> >> Simon >> >> >> +--- >> | Dr. Simon Anders, Dipl. Phys. >> | European Bioinformatics Institute, Hinxton, Cambridgeshire, UK >> | office phone +44-1223-492680, mobile phone +44-7505-841692 >> | preferred (permanent) e-mail: sanders@fs.tum.de >> > > [[alternative HTML version deleted]]