yes, it's in windows, you are so serious, Thanks so much, give me very good suggestion, i will try it. Thanks again. Best regards jun chen
On Mon, Oct 19, 2009 at 5:04 PM, <tlum...@u.washington.edu> wrote: > On Mon, 19 Oct 2009, Jun Chen wrote: > >> Dear, >> I would like to deal with microarray data, it can run when i deal with >> little data. However, the amount number of SNP data are 45181, amount >> numbers of animal are 3081,it can not be allocated 1000Mb memory when >> i importing them to R >> >> Procedure sentence show: >> >> m<-matrix(scan("D:/SNPdata.txt"),ncol=nmarkers,byrow=TRUE) >> >> Error show: >> Error: cannot allocate vector of size 1000.0 Mb > > It says you don't have enough memory. When stored as floating point numbers > the SNPs will take up 1Gb, which is quite a lot -- more than you can > conveniently analyze in a 32-bit version of R[*] -- you probably have more > than 1Gb of memory, but R does need to make copies of things. > > In my experience with SNP data, there are two strategies: storing the data > more efficiently (1 byte/SNP), as the Bioconductor package snpMatrix does, > or reading in just part of the data at a time (what I have usually done). > My approach is to read the data in chunks and store it in a netCDF file > with the ncdf package, and then at analysis time to read data as needed from > netCDF. This also works well for parallel processing -- many R sessions can > read efficiently from the netCDF file. > > > [*] you didn't provide the requested information about your system, but "D:" > looks Windows. > > -thomas > > Thomas Lumley Assoc. Professor, Biostatistics > tlum...@u.washington.edu University of Washington, Seattle > > -- Jun Chen Department of Animal Breeding and Genetics Göttingen University Albrecht-Thaer-Weg 3 37075 Göttingen ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.