Hi R users, I am trying to set the values of elements of one matrix based on the values of elements of another matrix. Say I have 2 matrices, y and z. y = matrix(rnorm(35), ncol=5) z = matrix(rep(0,35), ncol=5) I want z[i,j] to take a value of y[i,j] when y[i,j] is greater than 0, and zero otherwise. I was able to do it using the following loop: for(i in 1:7) { for(j in 1:5) { if(y[i,j]>0) { z[i,j]=y[i,j] } else { z[i,j]=0}} } but since my dataset is very large, looping often crashes. Is there a more elegant way I can achieve the same result? Many thanks!!! -- View this message in context: http://r.789695.n4.nabble.com/Evaluating-matrices-without-using-loops-tp2155574p2155574.html Sent from the R help mailing list archive at Nabble.com.