On Mon, Feb 04, 2008 at 03:21:10PM +0800, Ng Stanley wrote: > Hi, > > Given a test matrix, test <- matrix(c(1,2,3,NA,2,3,NA,NA,2), 3,3) > > A) How to compute the counts of each column (excluding the NA) i.e., 3, 2, 1
apply(test, 2, function(x) sum(!is.na(x))) > B) How to compute the counts of each column (excluding the NA) that are > greater than the column means ? i.e., 1, 1, 0 apply(test, 2, function(x) sum(x > mean(x, na.rm=TRUE), na.rm=TRUE)) In general, you need ?apply to calculate something for each row/column of a matrix. Gabor > I could write a for loop, but hope to use better alternative. > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. -- Csardi Gabor <[EMAIL PROTECTED]> UNIL DGM ______________________________________________ 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.
