This is probably a know problem (problem for me anyway) in R but I don't quite know what to search for in help archives. When I name a column "x11" in a data frame R thinks a column named "x1" exists. In my application I am trying to test for the existence of a column, then add it if it's not there. Here is a simple example:
> temd <- data.frame(x11=c(0:10)) > is.null(temd[["x1"]]) [1] FALSE > temd[["x1"]] [1] 0 1 2 3 4 5 6 7 8 9 10 > temd$x1 [1] 0 1 2 3 4 5 6 7 8 9 10 > temd[,"x1"] Error in "[.data.frame"(temd, , "x1") : undefined columns selected > This is in R 2.0.0. Anyone know how to run (safely) through a list of names like "x1"-"x100" and check for data frame columns with the names? ----------------------------------------------------------- * Opinions herein are mine only * ----------------------------------------------------------- Andrew Booker The Boeing Company P.O. Box 3707 MC 7L-22 Seattle, WA 98124-2207 425-865-3573 FAX# 425-865-2966 [EMAIL PROTECTED] ______________________________________________ [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