def test_scharr_h_vertical():
 (i, j) = np.mgrid[(-5):6, (-5):6]
 image = (j >= 0).astype(float)
 result = filters.scharr_h(image)
 assert_allclose(result, 0)

def test_scharr_h_vertical ( ) : ( i , j ) = np . mgrid [ ( - 5 ) : 6 , ( - 5 ) : 6 ] image = ( j >= 0 ) . astype ( float ) result = filters . scharr_h ( image ) assert_allclose ( result , 0 )
horizontal scharr on a vertical edge should be zero .