sum

Dear helpers

I have a list where each element is a matrix (the list is
obtained with lapply). I want to sum those matrices. Is there a
function to do that? The sum function sums all the elements...

If the list is not too long, perhaps

sumlist <- 
    function(x) 
        if (length(x) > 2) sumlist(x[1:2]) + 
             sumlist(x[-(1:2)]) else do.call("+", x) 



sumlist(<whatever your list is>)


-Deepayan