Hi, I have two (large) matrices A and B of dimensions (m,n) and (p,n) respectively.
I'd like to see if the is a fast way to compute a new matrix C with dimension (m*p,n) in which each row in C is found by applying some function f to each pair of rows (x,y) where x is a row in A and y is a row in B. For example, if A <- matrix(c(1, 2, 3, 4, 5, 6), byrow=TRUE, ncol=3) B <- matrix(c(7, 8, 9), byrow=TRUE, ncol=3) and f <- function(x,y) abs(y-x) then C <- matrix(c(6, 6, 6, 3, 3, 3), byrow=TRUE, ncol=3) Many thanks! Cheers, David ______________________________________________ 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.
