And here is a second way: > strapply(astr, "(\\w)\\w+", c, simplify = c) [1] "T" "i" "m" "t" "o" "w" "t" "d" "i" "i" "t" "f" "f" "T"
On Tue, Aug 4, 2009 at 1:42 PM, Gabor Grothendieck<ggrothendi...@gmail.com> wrote: > Try this: > >> library(gsubfn) >> strapply(astr, "\\w+", ~ substr(x, 1, 1), simplify = c) > [1] "T" "i" "m" "t" "o" "w" "t" "d" "i" "i" "t" "f" "f" "T" > > > On Tue, Aug 4, 2009 at 1:28 PM, ravi<rv...@yahoo.se> wrote: >> >> Hi, >> I am getting stuck over an apparently simple problem in the use of regular >> expressions : >> To collect together the first letters of the words from the Perl motto, >> “There is more than one way to do it” in the following form – TIMTOWTDI. >> I tried the following code : >> >> ##### A regex problem with the Perl motto >> astr<-"There is more than one way to do it" >> b1<-grep("\\<", astr,value=T) >> ## This just retrieves the whole string >> ## Next trial with gregexpr >> b2<-gregexpr("\\<",astr) >> ## This gives : >>> b3 >> [[1]] >> [1] 1 7 10 15 20 24 28 31 34 >> attr(,"match.length") >> [1] 0 0 0 0 0 0 0 0 0 >> >> A vector of indices corresponding to the first letter is obtained all right >> with gregexpr but the next step is not so clear. I am not able to figure out >> how I can use this information to pick out the letters from the original >> string. My problem is that I don’t know how I can treat the string as a >> vector and pluck out the letters. >> >> There may be many ways to do it, but I have not succeeded in coming up with >> even one way! I will appreciate any tips that I can get. >> Thanking you, >> Ravi >> >> ______________________________________________ >> 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.