Dear Christofer,
You can try the following:
# proccess the matrices
foo <- function(m1, m2){
if(ncol(m1) != ncol(m2)) stop('number of columns should be equal')
if(nrow(m1) < nrow(m2)){
nas <- matrix(NA, ncol = ncol(m1), nrow = nrow(m2) - nrow(m1))
m1 <- rbind(m1, nas)
}
else{
nas <- matrix(NA, ncol = ncol(m1), nrow = nrow(m1) - nrow(m2))
m2 <- rbind(m2, nas)
}
list(m1, m2)
}
# process
r <- foo(Mat1, Mat2)
# basic operations
Reduce("+", r)
Reduce("*", r)
Reduce("/", r)
Reduce("-", r)
HTH,
Jorge.-
On Fri, Jan 4, 2013 at 10:47 PM, Christofer Bogaso <> wrote:
Hello again,
Let say I have 2 matrices which equal number of columns but different
number of rows like:
Mat1 <- matrix(1:20, 4, 5)
Mat2 <- matrix(1:25, 5, 5)
Now for each column 1-to-5 I need to fetch the corresponding columns
of these 2 matrices and add the corresponding elements (ignoring NA
values if any). Therefore for the 1st column I need to do:
(1+1), (2+2),...,(4+4), (NA+5)
and so on
And the resulting numbers will be stored in some other matrix
Also note that, here I gave the example of addition, however, this can
be any user defined function.
Is there any R way to do that, without using any for-loop?
Thanks and regards,