1) Don't call your data.frame "data". I will call my "example" one "df".
2) If you want the columns NOT in names.species.bio.18, which is what you said, then the answer is: df[!names(df) %in% names.species.bio.18] Best, Erik -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of AllenL Sent: Monday, August 31, 2009 11:40 AM To: r-help@r-project.org Subject: [R] Simple column selection question- which and character lists Dear R-list, Seems simple but have tried multiple approaches, no luck. I have a list of column names: >names.species.bio.18=c("Achimillb","Agrosmitb","Amorcaneb","Andrgerab","Ascltubeb","Elymcanab","Koelcrisb","Lespcapib","Liataspeb","Lupipereb","Monafistb","Panivirgb","Petapurpb","Poaprateb","Querellib","Quermacrb","Schiscopb","Sorgnutab") I want to select the column numbers which correspond to these names in my data frame: >which(colnames(data)==names.species.bio.18) Result: +[1] 75 76 +Warning message: +In cols == names.species.bio.18 : + longer object length is not a multiple of shorter object length So I get the first two hits and then it trips an error message. What is >which doing? Why does it seem to have trouble with vectors of characters? My goal is to output the column names/indices which correspond to the columns NOT in the above list, but that is simple once I can find out what they are. Thanks! -Allen -- View this message in context: http://www.nabble.com/Simple-column-selection-question--which-and-character-lists-tp25226500p25226500.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. ______________________________________________ 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.
