Duncan, Of course my verbal descriptions and my code don't match my regexp - otherwise I wouldn't be asking the question, would I? Please assume my verbal descriptions are correctly describing what I want. Thank you!
On Thu, Sep 17, 2015 at 5:42 PM, Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > On 17/09/2015 5:11 PM, Dimitri Liakhovitski wrote: >> (x <- c("q10_1", "q10_2", "q10_11", "q12_1", "q12_2", "q13_1", "q13_11")) >> >> # Which strings start with "q10" or "q12? - WORKS >> x[grep("^q10|q12", x)] >> >> # Which strings end with "1"? - WORKS >> x[grep("1$", x)] >> >> # Which strings end with "_1"? - WORKS >> x[grep("\\_1$", x)] >> >> # Which strings start with "q10" AND contain a "1"? - WORKS >> x[grep("^q10.+1", x)] >> >> # Which strings start with "q10" AND end with a "_1"? - DOES NOT WORK >> x[grep("^q10.+\\_1$", x)] > > Your verbal description doesn't match your regexp, and you didn't show > us your output, so how can we tell whether this is you not understanding > regular expressions, or an actual problem? > > When I try this example, I get > > character(0) > > which is the correct outcome, given the input string. > > Duncan Murdoch > >> >> # Which strings start with "q10" or "q12 AND end with "_1"? - WORKS >> INCORRECTLY >> x[grep("^q10|q12.+\\_1$", x)] >> >> Thank you! >> Dimitri Liakhovitski >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. >> > -- Dimitri Liakhovitski ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.