sum all columns in a matrix

Given the folowing 2D matrix \(A\) ﬁnd the sum of each column

\(\begin {pmatrix} 1 & 2 & 3\\ 4 & 5 & 6\\ 7 & 8 & 9 \end {pmatrix}\)

Mathematica

In[3]:= mat={{1,2,3}, 
             {4,5,6}, 
             {7,8,9}} 
Total[mat,{1}] 
 
Out[4]= {12,15,18}

Matlab

A=[1 2 3;4 5 6;7 8 9]; 
sum(A,1) 
 
ans = 
    12    15    18

Maple

`add`~([LinearAlgebra:-Column(A,[1..-1])]) 
 
#      [12, 15, 18]