HI, If I understand your question correctly, this should give the result: dat1<-read.table(text=" A B C a b a x y z ",sep="",header=TRUE,stringsAsFactors=FALSE) within(dat1,{new_column<-ifelse(A==C|B==C,"y","n")}) # A B C new_column #1 a b a y #2 x y z n A.K.
----- Original Message ----- From: Sapana Lohani <lohani.sap...@ymail.com> To: R help <r-help@r-project.org> Cc: Sent: Tuesday, August 28, 2012 8:06 PM Subject: [R] Use or ?? Hi, My data frame looks like A B C a b a x y z I want to add a new column which says "y" if either A or B matches with C and "n" if there is no match. How can I do that? Thanks [[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.