Hi Anthony, Try this: x[,apply(x,2,function(x) !all(x==0))]
HTH, Jorge On Wed, Jan 14, 2009 at 5:01 PM, Anthony Dick <[email protected]> wrote: > Hello- > > I would like to remove the columns of a matrix that contain all zeros. For > example, from > x<-matrix(c(1,5,3,2,1,4,0,0,0), ncol=3,nrow=3) > > I would like to remove the third column. However, because this is in a loop > I need a way to first determine which columns are all zeros, and only then > remove them. I.e., I don't know which column of x contains all zeros until > after x is created. > > Thanks! > > Anthony > > -- > Anthony Steven Dick, Ph.D. > Post-Doctoral Fellow > Human Neuroscience Laboratory > Department of Neurology > The University of Chicago > 5841 S. Maryland Ave. MC-2030 > Chicago, IL 60637 > Phone: (773)-834-7770 > Email: [email protected] > Web: http://home.uchicago.edu/~adick/ > > ______________________________________________ > [email protected] 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. > [[alternative HTML version deleted]] ______________________________________________ [email protected] 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.
