Thank you Bill. John
________________________________ From: William Dunlap <wdun...@tibco.com> Sent: Mon, March 14, 2011 10:47:39 AM Subject: RE: [R] ideas on sorting > -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of array chip > Sent: Monday, March 14, 2011 10:33 AM > To: r-help@r-project.org > Subject: [R] ideas on sorting > > Hi, I have a character vector as below: > > a<-c('10','3R','4','4R','5','5R','6','6R','7','8','9','7R','1' > ,'10R','11' > ,'11R','12','12R','13','13R','14','14R','15','15R','1R','2','2 > R','3','8R' > ,'9R') > > Is there a clever way to sort this easily to return a vector > of index that would > produce a vector as below: > > a[index]: > > [1] "1" "2" "3" "4" "5" "6" "7" "8" "9" "10" > [11] "11" "12" "13" "14" "15" "1R" "2R" "3R" "4R" "5R" > [21] "6R" "7R" "8R" "9R" "10R" "11R" "12R" "13R" "14R" "15R" Break up the strings into an initial number (as a number, not a string, for they sort differently) and a trailing string starting with the first non-digit. Order them by the trailing string, breaking ties with the initial number: > index <- order(gsub("^[[:digit:]]+", "", a), # trailing string as.integer(gsub("([[:digit:]]+).*$", "\\1", a))) # break ties with initial numbers > a[index] [1] "1" "2" "3" "4" "5" "6" "7" "8" "9" "10" "11" "12" [13] "13" "14" "15" "1R" "2R" "3R" "4R" "5R" "6R" "7R" "8R" "9R" [25] "10R" "11R" "12R" "13R" "14R" "15R" Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > > Thanks, > > John > > > > [[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. > [[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.
