def test_implicitize_bad_dimension(self):
nodes = np.empty((1, 2), order="F")
curve = self._make_one(nodes, 1, copy=False)
with self.assertRaises(ValueError) as exc_info:
curve.implicitize()
exc_args = exc_info.exception.args
self.assertEqual(
exc_args,
(
"Only a planar (2D) curve can be implicitized",
"Current dimension",
1,
),
)
def test_implicitize(self):
nodes = np.asfortranarray([[3, 3, 4, 6], [3, 3, 3, 0]])
curve = self._make_one(nodes, 3, copy=False)
f_polynomial = curve.implicitize()
x_sym, y_sym = sympy.symbols("x, y")
expected = -9 * (x_sym**3 - 9 * x_sym**2 + 27 * x_sym - 3 * y_sym**2 +
18 * y_sym - 54)
self.assertTrue(test__symbolic.sympy_equal(f_polynomial, expected))