remove columns containing all zeros (or other value)
You can also try this: x[,-(which(colSums(x) == 0))] Cheers, Gustavo.
On Wed, Jan 14, 2009 at 8:01 PM, Anthony Dick <adick at uchicago.edu> 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: adick at uchicago.edu Web: http://home.uchicago.edu/~adick/
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