Hi, I didn't think about the situation where D comes before T. I changed my code a little to accommodate that.
dat2<-read.table(text=" 1 0000000000D0000000000000000000000000000000000000 0.007368; 2 0000000000d0000000000000000000000000000000000000 0.002456; 3 000000000T00000000000000000000000000000000000000 0.007368; 4 000000000DT0000000000000000000000000000000000000 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; ",sep="",header=FALSE) colnames(dat2)<-c("num","Ch", "count") dat2[grepl("0T|0Td|0TD",dat2$Ch),] num Ch count 3 3 000000000T00000000000000000000000000000000000000 0.007368; 5 5 000000000T00000000000000000000000000000000000000 0.002456; 6 6 000000000Td0000000000000000000000000000000000000 0.002456; 7 7 00000000T000000000000000000000000000000000000000 0.007368; 8 8 00000000T0D0000000000000000000000000000000000000 0.007368; 9 9 00000000T000000000000000000000000000000000000000 0.002456; 10 10 00000000T0d0000000000000000000000000000000000000 0.002456; A.K. ----- Original Message ----- From: Rui Barradas <ruipbarra...@sapo.pt> To: Claudia Penaloza <claudiapenal...@gmail.com> Cc: r-help@r-project.org Sent: Monday, July 2, 2012 7:24 PM Subject: Re: [R] Removing rows if certain elements are found in character string Hello, Try regular expressions instead. In this data.frame, I've changed row nr.4 to have a row with 'D' as first non-zero character. dd <- read.table(text=" ch count 1 0000000000D0000000000000000000000000000000000000 0.007368 2 0000000000d0000000000000000000000000000000000000 0.002456 3 000000000T00000000000000000000000000000000000000 0.007368 4 000000000DT0000000000000000000000000000000000000 0.007368 5 000000000T00000000000000000000000000000000000000 0.002456 6 000000000Td0000000000000000000000000000000000000 0.002456 7 00000000T000000000000000000000000000000000000000 0.007368 8 00000000T0D0000000000000000000000000000000000000 0.007368 9 00000000T000000000000000000000000000000000000000 0.002456 10 00000000T0d0000000000000000000000000000000000000 0.002456 ", header=TRUE) dd i1 <- grepl("^([0D]|[0d])*$", dd$ch) i2 <- grepl("^0*[Dd]", dd$ch) dd[!i1, ] dd[!i2, ] dd[!(i1 | i2), ] Hope this helps, Rui Barradas Em 02-07-2012 23:48, Claudia Penaloza escreveu: > 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. ______________________________________________ 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.