You'll want to use grep() or grepl(). By default, grep() uses extended regular expressions to find matches, but you can also use perl regular expressions and globbing (after converting to a regular expression). For example:
grepl("^yr", colnames(mydata)) will tell you which 'colnames' start with "yr". If you'd rather you use globbing: grepl(glob2rx("yr*"), colnames(mydata)) Then you might write something like this to remove the columns starting with yr: mydata <- mydata[, !grepl("^yr", colnames(mydata)), drop = FALSE] On Sat, Jan 14, 2023 at 1:56 AM Steven T. Yen <st...@ntu.edu.tw> wrote: > > I have a data frame containing variables "yr3",...,"yr28". > > How do I remove them with a wild card----something similar to "del yr*" > in Windows/doc? Thank you. > > > colnames(mydata) > [1] "year" "weight" "confeduc" "confothr" "college" > [6] ... > [41] "yr3" "yr4" "yr5" "yr6" "yr7" > [46] "yr8" "yr9" "yr10" "yr11" "yr12" > [51] "yr13" "yr14" "yr15" "yr16" "yr17" > [56] "yr18" "yr19" "yr20" "yr21" "yr22" > [61] "yr23" "yr24" "yr25" "yr26" "yr27" > [66] "yr28"... > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.