> x <- array(-10:10, dim=c(4,5)) > x [,1] [,2] [,3] [,4] [,5] [1,] -10 -6 -2 2 6 [2,] -9 -5 -1 3 7 [3,] -8 -4 0 4 8
It appears that the order of the arguments to pmax() affects the class of what is returned when the input is a matrix:
pmax()
pmax(0,x) [1] 0 0 0 0 0 0 0 0 0 0 0 1 2 3 4 5 6 7 8 9 pmax(x,0) [,1] [,2] [,3] [,4] [,5] [1,] 0 0 0 2 6 [2,] 0 0 0 3 7 [3,] 0 0 0 4 8 [4,] 0 0 1 5 9