Bernd Jagla wrote: > It helps writing down these question, you are then getting much closer to an > answer... > > summary(as.integer(t3[,2]) == as.integer(t3[,4]) & as.integer(t3[,3]) == > as.integer(t3[,5])) > > will compare two pairs of column pairs and give a count of flase and true > rows... > > If they really are factors with different level sets, I think you might prefer as.character() there.
> x <- factor(c("a","b")) > y <- factor(c("b","c")) > x==y Error in Ops.factor(x, y) : level sets of factors are different > as.integer(x)==as.integer(y) [1] TRUE TRUE > as.character(x)==as.character(y) [1] FALSE FALSE Also, extending the above slightly: > d <- as.character(x)==as.character(y) > table(d) d FALSE TRUE 2 1 > which(!d) [1] 1 2 > -B > > |-----Original Message----- > |From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > |Behalf Of Bernd Jagla > |Sent: Friday, November 30, 2007 10:25 PM > |To: r-help@r-project.org > |Subject: [R] compare strings > | > |Sorry for the question, but I really cannot find the right search terms to > |find an answer.. > | > | > | > |I have a data frame with strings in some of the columns. > | > |I want to know all the rows where the strings in both columns are equal. > | > | > | > |How do I do this? > | > | > | > |Thanks, > | > | > | > |Bernd > | > | > | [[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. > -- O__ ---- Peter Dalgaard Ă˜ster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ 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.