Hi Katherine, May be this helps:
df[!duplicated(lapply(df,summary))] # id x y z #1 1 15 36 D #2 2 21 38 B #3 3 14 55 A #4 4 21 11 F #5 5 14 5 H #6 6 38 18 P #or df[,colnames(unique(as.matrix(df),MARGIN=2))] # id x y z #1 1 15 36 D #2 2 21 38 B #3 3 14 55 A #4 4 21 11 F #5 5 14 5 H #6 6 38 18 P A.K. ----- Original Message ----- From: Katherine Gobin <katherine_go...@yahoo.com> To: r-help@r-project.org Cc: Sent: Thursday, March 28, 2013 4:39 AM Subject: [R] How to delete Identical columns Dear R forum Suppose I have a data.frame df = data.frame(id = c(1:6), x = c(15, 21, 14, 21, 14, 38), y = c(36, 38, 55, 11, 5, 18), x.1 = c(15, 21, 14, 21, 14, 38), z = c("D", "B", "A", "F", "H", "P")) > df id x y x.1 z 1 1 15 36 15 D 2 2 21 38 21 B 3 3 14 55 14 A 4 4 21 11 21 F 5 5 14 5 14 H 6 6 38 18 38 P Clearly columns x and x.1 are identical. In reality, I have a large data.frame and can't make out which columns are identical, but I am sure that column with name say x is repeated as x.1, x.2 etc. How to automatically identify and retain only one column (in this example column x) among the identical columns besides other non-identical columns (viz. id, y and z). Regards Katherine [[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. ______________________________________________ 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.