Seems to work fine for me. You need to read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. You did not provide 'source', so I created one and it seems to work. So I have to conclude you have something wrong in your data.
> hm_acc <- c("XM_528056","AB002296") > source <- data.frame(V1=c("XM_528056","AB002296"), V2=1:2) > for (i in 1:length(hm_acc)){ + + hm_acc_id <- as.character(hm_acc[i]) + print(hm_acc_id) + + hm_allk <- grep(hm_acc_id,source$V1) + hm_all <- source[hm_allk,] + + print(hm_all) + } [1] "XM_528056" V1 V2 1 XM_528056 1 [1] "AB002296" V1 V2 2 AB002296 2 > On Mon, Oct 6, 2008 at 7:37 AM, Gundala Viswanath <[EMAIL PROTECTED]> wrote: > Dear all, > > I have no problem with this individual grep command: > >> datk <- grep("XM_528056", source$V1) >> dat2 <- source[datk,] >> print(dat2) > V1 V2 V3 V4 V5 V6 V7 > 35995 XM_528056 panTro2 chr8 + 1775569 1896107 Chimpanzee > > > BUT, when I run them under the loop it gives this error: > > >> hm_acc <- c("XM_528056","AB002296") >> for (i in 1:length(hm_acc)){ > + > + hm_acc_id <- as.character(hm_acc[i]) > + print(hm_acc_id) > + > + hm_allk <- grep(hm_acc_id,source$V1) > + hm_all <- source[hm_allk,] > + > + print(hm_all) > + } > > [1] "XM_528056" > [1] V1 V2 V3 V4 V5 V6 V7 > <0 rows> (or 0-length row.names) > [1] "AB002296" > [1] V1 V2 V3 V4 V5 V6 V7 > <0 rows> (or 0-length row.names) > ..... > > What's wrong with my way of using grep? > Please advice. > > > - Gundala Viswanath > Jakarta - Indonesia > > ______________________________________________ > 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.