Re: [R] how to get to interesting part of pattern match
Vadim Ogranovich wrote: Hi, I am looking for a way to extract an interesting part of the match to a regular expression. For example the pattern [./](*.) matches a substring that begins with either . or / followed by anything. I am interested in this anything w/o the . or / prefix. If say I match the pattern against abc/foo I want to get foo, not /foo. In Perl one can simply wrap the interesting part in () and get it out of the match. Is it possible to do a similar thing in R? There seems to be a way to refer to the match, see below, but I couldn't figure out how to make gsub return it. gsub([./](*.), \\1, abc/foo) [1] abcfoo Thanks, Vadim __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html what about: gsub(.*[./](*.), \\1, abc/foo) output-start [1] foo output-end or try: strsplit(abc/foo,/)[[1]][2] output-start [1] foo output-end Peter Wolf __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] how to get to interesting part of pattern match
sub(.*/, , abc/foo) [1] foo Jean On Thu, 18 Nov 2004, Vadim Ogranovich wrote: Hi, I am looking for a way to extract an interesting part of the match to a regular expression. For example the pattern [./](*.) matches a substring that begins with either . or / followed by anything. I am interested in this anything w/o the . or / prefix. If say I match the pattern against abc/foo I want to get foo, not /foo. In Perl one can simply wrap the interesting part in () and get it out of the match. Is it possible to do a similar thing in R? There seems to be a way to refer to the match, see below, but I couldn't figure out how to make gsub return it. gsub([./](*.), \\1, abc/foo) [1] abcfoo Thanks, Vadim __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] how to get to interesting part of pattern match
Vadim Ogranovich vograno at evafunds.com writes: : I am looking for a way to extract an interesting part of the match to : a regular expression. For example the pattern [./](*.) matches a : substring that begins with either . or / followed by anything. I am : interested in this anything w/o the . or / prefix. If say I match : the pattern against abc/foo I want to get foo, not /foo. In Perl : one can simply wrap the interesting part in () and get it out of the : match. Is it possible to do a similar thing in R? : : There seems to be a way to refer to the match, see below, but I couldn't : figure out how to make gsub return it. : gsub([./](*.), \\1, abc/foo) : [1] abcfoo Assuming what was meant is the following (dot and star are transposed and gsub is sub): sub([./](.*), \\1, abc/foo) then the regular expression matches /foo and the backreference contains foo so it replaces /foo with foo which is why it returns abcfoo . To get just foo ensure that your regular expression matches the entire string so that the entire string is replaced with the backreference: sub([^./]*[./](.*), \\1, abc/foo) __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
