4.2. Uniform vectorization/Python implementation bug

[vladislavneon]

There's a shape inconsistency in compute_neighbours function:

def compute_neighbours(Z):
    shape = len(Z), len(Z[0])
    N  = [[0,]*(shape[0]) for i in range(shape[1])]
    for x in range(1,shape[0]-1):
        for y in range(1,shape[1]-1):
            N[x][y] = Z[x-1][y-1]+Z[x][y-1]+Z[x+1][y-1] \
                    + Z[x-1][y]            +Z[x+1][y]   \
                    + Z[x-1][y+1]+Z[x][y+1]+Z[x+1][y+1]
    return N

Shape of N is currently a transposed shape of Z, which would result in index of out range exception in case of non-square field.

Not critical for the example, but a bit confusing anyway.

[rougier]

Good point.