Hi, You could get the result: dat1 <- read.table(text = " v1 v2 v3 1 0 0 0 1 0 0 0 1 ",sep="",header=TRUE)
dat1$v4<-apply(mapply(`==`,dat1,1),2,which) dat1 # v1 v2 v3 v4 #1 1 0 0 1 #2 0 1 0 2 #3 0 0 1 3 A.K. ----- Original Message ----- From: Winfried Moser <winfried.mo...@gmail.com> To: r-help <r-help@r-project.org> Cc: Sent: Thursday, February 7, 2013 12:20 PM Subject: [R] why "object 'x' not found"? Dear Listers, I try to change the structure of my data. i have an indicator-matrix and want to end up with a factor. i have v1 v2 v3 1 0 0 0 1 0 0 0 1 and want v1 v2 v3 v4 1 0 0 1 0 1 0 2 0 0 1 3 amongst other things i tried the following d <- data.frame(d1=c(1,0,0), d2=c(0,1,0), d3=c(0,0,1)) d$nr <- NA sapply(1:3, function(x) ifelse(get(paste0("d$d",x))==1,x,d$nr)) >From R i get the message "Object 'd$d1' not found". But why, it's there? Thanks a lot. Winfried [[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.