def proj_transform(xs, ys, zs, M):
 vec = vec_pad_ones(xs, ys, zs)
 return proj_transform_vec(vec, M)

def proj_transform ( xs , ys , zs , M ) : vec = vec_pad_ones ( xs , ys , zs ) return proj_transform_vec ( vec , M )
transform the points by the projection matrix .