try this: mat <- matrix(rnorm(42), 6, 7) mat[sample(42, 10)] <- NA mat[, c(3,5)] <- NA
ind <- colSums(is.na(mat)) != nrow(mat) mat mat[, ind] I hope it helps. Best, Dimitris ---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/(0)16/336899 Fax: +32/(0)16/337015 Web: http://med.kuleuven.be/biostat/ http://www.student.kuleuven.be/~m0390867/dimitris.htm ----- Original Message ----- From: "Martin Waller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, February 14, 2008 1:59 PM Subject: [R] Removing columns that are all NA from a matrix > Hi, > > I guess this might be a FAQ or something, and there's probably a > nice > simple way to do it, but I can't think of it: > > Given a matrix, I want to remove columns that are _entirely_ filled > with > NAs (partial NAs are fine). > > How please? > > Thanks, > > Martin > > ______________________________________________ > 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. > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm ______________________________________________ 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.