help

If your matrices are the same size, you can just add them. If they aren't the
same size, I'm not sure what you are trying to accomplish.

mat1 <- matrix(1:9, nrow=3)
mat1

[,1] [,2] [,3]
[1,]    1    4    7
[2,]    2    5    8
[3,]    3    6    9

mat2 <- matrix(runif(9), nrow=3)
mat2

[,1]      [,2]      [,3]
[1,] 0.54837515 0.3476839 0.6298484
[2,] 0.25790633 0.3394281 0.3601670
[3,] 0.08251705 0.2288201 0.4216952

mat1 + mat2

[,1]     [,2]     [,3]
[1,] 1.548375 4.347684 7.629848
[2,] 2.257906 5.339428 8.360167
[3,] 3.082517 6.228820 9.421695

Someone knows the existence of a function to sum the elements of the same
place A[i,j] B[i,j] of a matrix?thank you

Sarah Goslee
http://www.functionaldiversity.org