Is there any better way to deal with such loop structure?

Here's the algorithm for which I need to create a loop structure

for i = 0 to wrow-1
for j = 0 to wcol
    net[i] = net[i] + w[i][j] * input[?]
end j for
end i for

Where wrow&wcol is a 2d matrix[wrow][wcol] array with size [3][3]. input is a 3d array or a 3d vector.