Thanks, both of these methods work great!
Dimitris Rizopoulos-4 wrote: > > one way is: > > mat <- > matrix(c(rep(NA,10),1,2,3,4,5,6,7,8,9,10,10,9,8,NA,6,5,4,NA,2,1,rep(NA,10),1,2,3,4,NA,6,7,8,9,10), > > 10, 5) > ind <- colSums(is.na(mat)) != nrow(mat) > mat[, ind] > > > I hope it helps. > > Best, > Dimitris > > > dxc13 wrote: >> useR's, >> I have a matrix given by the code: >> mat <- >> matrix(c(rep(NA,10),1,2,3,4,5,6,7,8,9,10,10,9,8,NA,6,5,4,NA,2,1,rep(NA,10),1,2,3,4,NA,6,7,8,9,10),10,5) >> >> This is a 10x5 matrix containing missing values. All columns except the >> second contain missing values. I want to delete all columns that contain >> ALL missing values, and in this case, it would be the first and fourth >> columns. Any column that has at least one real number would remain. I >> know >> I can use "mat[,-1]" to delete the first column, but I have a much larger >> matrix where it is impossible to tell how many columns contain all >> missing >> values and which don't. >> Is there a function or something else that may be able to help me >> accomplish >> this? >> >> Thanks in advance. >> dxc13 > > -- > Dimitris Rizopoulos > Assistant Professor > Department of Biostatistics > Erasmus University Medical Center > > Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands > Tel: +31/(0)10/7043478 > Fax: +31/(0)10/7043014 > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/Deleting-columns-from-a-matrix-tp23695656p23696294.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.
