Dear list, I have a list of three matrices :
i = list(matrix(1:4,2,2), matrix(3:6,2,2), matrix(9:12,2,2)) I would like to sum the matrices, as follows : [,1] [,2] [1,] 13 19 [2,] 16 22 I used this code : k <- i[[1]] for (j in (2:length(i))) { k <- k + i[[j]]} But, is it possible to sum without a loop ? Thanks in advance, Carlos [[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.