search for: nxnx1000

Hi, I got 1000 NxN matrices grouped in one array. I want one matrix in which p_ij is the average of all the 1000 matrices in the array. Here's what I'm trying to do: # P is the NxNx1000 array for(i in 1:N) for(j in 1:N) for(k in 1: 1000) mymat[ i, j ] <- mean( P [i , j , k ] ) Otherwise, I could have a NxNx1000 vector, and get the N^2 means of the 1+ (N^2)*(0: 999) elements. I don't know which is more efficient, but I wouldn't know how to carry this last solution out...