Y = sum_col(X) (Matrix|Array|Index) Y; (Matrix|Array|Index) X;
>> Y = sum_col([[1 2][3 4]])
=== [Y] : ( 1, 2) ===
( 1) ( 2)
( 1) 4.00000000E+00 6.00000000E+00
>> Y = sum_col([1 3])
=== [Y] : ( 1, 1) ===
( 1)
( 1) 4.00000000E+00