# trying to do a copy and a transform within a data frame, but getting the "arguments imply differing number of rows" error, and I'm not sure why
a=c(1,2,3) b=c(2,3,4) c=c("Yes","No","Yes") d=c("No","Yes","No") df=data.frame(a,b,c,d) # the following works fine! df = transform(df, new=sapply(df[,c(1,2)], FUN = function(x) { x^2 } )) # but the following doesn't work: num_value = function(x) { if (x == "Yes") { return(1) } else if (x == "No") { return(0) } else return(NA) } df = transform(df, new=sapply(df[,c(3,4)], FUN = num_value )) # generates this error.. Error in data.frame(list(a = c(1, 2, 3), b = c(2, 3, 4), c = c(2L, 1L, : arguments imply differing number of rows: 3, 2 # thanks for the help! -- View this message in context: http://r.789695.n4.nabble.com/error-when-copy-and-transform-within-a-data-frame-tp2293686p2293686.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.