Jeremie, i'm not totally sure i understand your desire. but, does this help?
---- mx <- max(nchar(mat), na.rm=TRUE) apply( mat,1, function(x) { x[is.na(x)] <-"" cat(sprintf("%*s", mx, x), "\n") }) ---- cheers, Greg ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.