def test_scalar_potential():
assert scalar_potential(Vector.zero, C) == 0
assert scalar_potential(i, C) == x
assert scalar_potential(j, C) == y
assert scalar_potential(k, C) == z
assert scalar_potential(y * z * i + x * z * j + x * y * k, C) == x * y * z
assert scalar_potential(grad_field, C) == scalar_field
assert scalar_potential(z * P.i + P.x * k, C) == x * z * cos(q) + y * z * sin(q)
assert scalar_potential(z * P.i + P.x * k, P) == P.x * P.z
raises(ValueError, lambda: scalar_potential(x * j, C))
def test_scalar_potential():
assert scalar_potential(Vector.zero, C) == 0
assert scalar_potential(i, C) == x
assert scalar_potential(j, C) == y
assert scalar_potential(k, C) == z
assert scalar_potential(y*z*i + x*z*j + x*y*k, C) == x*y*z
assert scalar_potential(grad_field, C) == scalar_field
assert scalar_potential(z*P.i + P.x*k, C) == x*z*cos(q) + y*z*sin(q)
assert scalar_potential(z*P.i + P.x*k, P) == P.x*P.z
raises(ValueError, lambda: scalar_potential(x*j, C))
