function y = sumCols(A)
%SUMCOLS Column sums of a matrix
%   y = sumCols(A) returns a row vector of the column sums of A.

[rows, cols] = size(A);
y = zeros(1, cols);
for c = 1:cols
    for r = 1:rows
        a = A(r, c);
        y(c) = y(c) + a;
    end
end
