search for: summatrices

...to do: *d=3 k=2 T=4 X = array(rnorm(d*k*T),dim=c(d,k,T)) A = matrix(rnorm(d*d),d,d) e1 = list() for (t in 1:T){ #I would like to avoid this e1[[t]] = t(X[,,t])%*%A%*%X[,,t] } ############################## #Function for doing the sum of matrices in a list ############################## sumMatrices <- function(matrices){ if (length(matrices) > 2) matrices[[1]] + Recall(matrices[-1]) else matrices[[1]] + matrices[[2]] } ############################## result = sumMatrices(e1) * Thank you in advance for all your help, best Michela [[alternative HTML version deleted]]

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... -- http://adsl.sapo.pt