Hello, Better yet is function aggregate.
# Create some data matrix Y <- matrix(c(sample(80, 507, TRUE), sample(-1:1, 4*507, TRUE)), ncol=5) X <- aggregate(Y[, 5]~Y[, 1], Y, sum) # In your case Y[, 4] not Y[, 1] Hope this helps, Rui Barradas Em 05-06-2012 09:53, Özgür Asar escreveu:
Hi, x<-matrix(0,80,ncol=1) will create x matrix with all elements 0 (to be filled by the sums that you need) sum(y[y[,4]==1,5]) will calculate the sum of 5th column of y with 4th column=1 Similarly, sum(y[y[,4]==80,5]) will calculate the sum of 5th column of y with 4th column=80. You can adapt this to your case, with simple loops, etc. Hope this helps. Ozgur -- View this message in context: http://r.789695.n4.nabble.com/Summarizing-a-matrix-tp4632319p4632381.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.
______________________________________________ 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.
