Jim's solution is more elegant than the following (and probably more efficient) but you could also try the following (This let's you sort by AN/HN, and then by the number at the start of the filename):
> text <- c( "26M_AN_C.bmp", "22M_AN_C.bmp", "20M_HA_O.bmp", "20M_AN_C.bmp", "26M_HA_O.bmp", "22M_HA_O.bmp", "31M_AN_C.bmp", "38M_HA_O.bmp") > split <- do.call("rbind",strsplit(text,"_")) > o <- order(split[,2],split[,1],split[,3]) > text[o] [1] 20M_AN_C.bmp" "22M_AN_C.bmp" "26M_AN_C.bmp" "31M_AN_C.bmp" "20M_HA_O.bmp" [6] "22M_HA_O.bmp" "26M_HA_O.bmp" "38M_HA_O.bmp" -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Alice Lin Sent: Wednesday, January 28, 2009 3:38 PM To: r-help@r-project.org Subject: [R] Text data i have a data column of text entries: 26M_AN_C.bmp 22M_AN_C.bmp 20M_HA_O.bmp 20M_AN_C.bmp 26M_HA_O.bmp 22M_HA_O.bmp 31M_AN_C.bmp 38M_HA_O.bmp . . . . And I would like to sort by the middle tag: AN, HA, etc. Is there a way to parse text data in R? In excel, I would have used the "left" and "right" function to cut out just the middle two letters out and put into another column to sort by. Thanks! -- View this message in context: http://www.nabble.com/Text-data-tp21714334p21714334.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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. =================================== P Please consider the environment before printing this e-mail Cleveland Clinic is ranked one of the top hospitals in America by U.S. News & World Report (2008). Visit us online at http://www.clevelandclinic.org for a complete listing of our services, staff and locations. Confidentiality Note: This message is intended for use\...{{dropped:13}} ______________________________________________ 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.