def scaling(x=1, y=1, z=1):
 s = np.array([[x, 0, 0, 0], [0, y, 0, 0], [0, 0, z, 0], [0, 0, 0, 1]], dtype=float)
 return s

def scaling ( x = 1 , y = 1 , z = 1 ) : s = np . array ( [ [ x , 0 , 0 , 0 ] , [ 0 , y , 0 , 0 ] , [ 0 , 0 , z , 0 ] , [ 0 , 0 , 0 , 1 ] ] , dtype = float ) return s
create an array with a scaling matrix .