Hi Folks, I'm trying to extract just the backreferences from a regex.> temp = "abcd1234abcd1234" > regmatches(temp, gregexpr("(?:abcd)(1234)", temp))[[1]] [1] "abcd1234" "abcd1234" What I would like is: [1] "1234" "1234" Note: I know I can just match 1234 here, but the actual example is complicated enough that I have to match a larger string, and just want to pass out the backreferenced portion. Any help greatly appreciated! Thanks, Allie
On Fri, Nov 2, 2012 at 6:02 PM, Alexander Shenkin <ashenkin at ufl.edu> wrote:> Hi Folks, > > I'm trying to extract just the backreferences from a regex. > >> temp = "abcd1234abcd1234" >> regmatches(temp, gregexpr("(?:abcd)(1234)", temp)) > [[1]] > [1] "abcd1234" "abcd1234" > > What I would like is: > [1] "1234" "1234" > > Note: I know I can just match 1234 here, but the actual example is > complicated enough that I have to match a larger string, and just want > to pass out the backreferenced portion. > > Any help greatly appreciated! >Try this:> library(gsubfn) > strapplyc(temp, "abcd(1234)")[[1]] [1] "1234" "1234" -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com
HI, I am not sure whether this helps: temp1<-regmatches(temp, gregexpr("(?:abcd)(1234)", temp)) #your code substr(unlist(temp1),5,8) #[1] "1234" "1234" A.K. ----- Original Message ----- From: Alexander Shenkin <ashenkin at ufl.edu> To: r-help at r-project.org Cc: Sent: Friday, November 2, 2012 6:02 PM Subject: [R] backreferences in gregexpr Hi Folks, I'm trying to extract just the backreferences from a regex.> temp = "abcd1234abcd1234" > regmatches(temp, gregexpr("(?:abcd)(1234)", temp))[[1]] [1] "abcd1234" "abcd1234" What I would like is: [1] "1234" "1234" Note: I know I can just match 1234 here, but the actual example is complicated enough that I have to match a larger string, and just want to pass out the backreferenced portion. Any help greatly appreciated! Thanks, Allie ______________________________________________ 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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