testy.py

sobel_vertical = nd.array((
    (1,0,-1),
    (2,0,-2),
    (1,0,-1)
))

print("\nSobel vertical transform Gx", end='')
print(sobel_vertical)
rotation_90_x = nd.array((
    (  1,  0,  0),
    (  0,  0, -1),
    (  0,  1,  0)
))
rotation_90_y = nd.array((
    (  0,  0,  1),
    (  0,  1,  0),
    ( -1,  0,  0)
))
rotation_90_z = nd.array((
    (  0, -1,  0),
    (  1,  0,  0),
    (  0,  0,  1)
))

#rotation = rotation_90_try2
#print("\nChose rotation matrix", end='')
#print(rotation)
#k = rotation_90_x * sobel_vertical
#k = nd.dot(rotation_90_x, sobel_vertical)
#k = rotation_90_x * sobel_vertical.T
#k = nd.dot(rotation_90_x, sobel_vertical.T)

#k = rotation_90_y * sobel_vertical
#k = nd.dot(rotation_90_y, sobel_vertical)
#k = rotation_90_y * sobel_vertical.T
# this one came close
#k = nd.dot(rotation_90_y, sobel_vertical.T)

k = rotation_90_z * sobel_vertical
#k = nd.dot(rotation_90_z, sobel_vertical)
#k = rotation_90_z * sobel_vertical.T
#k = nd.dot(rotation_90_z, sobel_vertical.T)


print("\nKernel to apply", end='')
print(k)