[R] How to get row numbers of a subset of rows
affy snp
affysnp at gmail.com
Wed Nov 14 20:45:37 CET 2007
Thank you very much, Julian. I got it.
Best,
Allen
On Nov 14, 2007 2:38 PM, Julian Burgos <jmburgos at u.washington.edu> wrote:
> One way to do this is
>
> range(which(B[,2]==1))
>
> Julian
>
>
> affy snp wrote:
> > Hello list,
> >
> > I read in a txt file using
> >
> > <B<-read.table(file="data.snp",header=TRUE,row.names=NULL)
> >
> > by specifying the row.names=NULL so that the rows are numbered.
> > Below is an example after how the table looks like using
> > <B[1:10,1:3]
> >
> >
> > SNP Chromosome PhysicalPosition
> > 1 SNP_A-1909444 1 7924293
> > 2 SNP_A-2237149 1 8173763
> > 3 SNP_A-4303947 1 8191853
> > 4 SNP_A-2236359 1 8323433
> > 5 SNP_A-2205441 1 8393263
> > 6 SNP_A-1909445 1 7924293
> > 7 SNP_A-2237146 2 8173763
> > 8 SNP_A-4303946 2 8191853
> > 9 SNP_A-2236357 2 8323433
> > 10 SNP_A-2205442 2 8393263
> >
> > I am wondering if there is a way to return the start and end row numbers
> > for a subset of rows.
> >
> > For example, If I specify B[,2]=1, I would like to get
> > start=1 and end=6
> >
> > if B[,2]=2, then start=7 and end=10
> >
> > Is there any way in R to quickly do this?
> >
> > Thanks a bunch!
> >
> > Allen
> >
>
> > ______________________________________________
> > R-help at 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.
>
>
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