Perhaps I've missed something, but if it's really true that the goal is to remove rows if the first non-zero element is "D" or "d", then how about this:
tmp <- gsub('0','',df$ch) first <- substr(tmp,1,1) subset(df, tolower(first) != 'd') and of course it could be rolled up into a single expression, but I wrote it in several steps to make it easy to follow. No need to wrap one's brain around regular expressions (which is hard for me!) -Don -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 7/2/12 3:48 PM, "Claudia Penaloza" <claudiapenal...@gmail.com> wrote: >I would like to remove rows from the following data frame (df) if there >are >only two specific elements found in the df$ch character string (I want to >remove rows with only "0" & "D" or "0" & "d"). Alternatively, I would like >to remove rows if the first non-zero element is "D" or "d". > > > ch count >1 0000000000D0000000000000000000000000000000000000 0.007368; >2 0000000000d0000000000000000000000000000000000000 0.002456; >3 000000000T00000000000000000000000000000000000000 0.007368; >4 000000000TD0000000000000000000000000000000000000 0.007368; >5 000000000T00000000000000000000000000000000000000 0.002456; >6 000000000Td0000000000000000000000000000000000000 0.002456; >7 00000000T000000000000000000000000000000000000000 0.007368; >8 00000000T0D0000000000000000000000000000000000000 0.007368; >9 00000000T000000000000000000000000000000000000000 0.002456; >10 00000000T0d0000000000000000000000000000000000000 0.002456; > > >I tried the following but it doesn't work if there is more than one >character per string: > >>df <- df[!df$ch %in% c("0","D"),] >>df <- df[!df$ch %in% c("0","d"),] > >Any help greatly appreciated, >Claudia > > [[alternative HTML version deleted]] > >______________________________________________ >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. ______________________________________________ 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.