def test_5th_order_polynomial(self):
# this should be an exact fit
f = lambda x: x**4 + x**3 - 2 * x**2 + 4 * x + 5
f_prime = lambda x: 4 * x**3 + 3 * x**2 - 4 * x + 4
coeffs = odes._interp_fit(f(0.0), f(10.0), f(5.0), f_prime(0.0),
f_prime(10.0), 10.0)
times = np.linspace(0, 10, dtype=np.float32)
y_fit = tf.stack(
[odes._interp_evaluate(coeffs, 0.0, 10.0, t) for t in times])
y_expected = f(times)
with self.test_session() as sess:
y_actual = sess.run(y_fit)
self.assertAllClose(y_expected, y_actual)
# attempt interpolation outside bounds
y_invalid = odes._interp_evaluate(coeffs, 0.0, 10.0, 100.0)
with self.test_session() as sess:
with self.assertRaises(tf.errors.InvalidArgumentError):
sess.run(y_invalid)
def test_5th_order_polynomial(self):
# this should be an exact fit
f = lambda x: x**4 + x**3 - 2 * x**2 + 4 * x + 5
f_prime = lambda x: 4 * x**3 + 3 * x**2 - 4 * x + 4
coeffs = odes._interp_fit(
f(0.0), f(10.0), f(5.0), f_prime(0.0), f_prime(10.0), 10.0)
times = np.linspace(0, 10, dtype=np.float32)
y_fit = array_ops.stack(
[odes._interp_evaluate(coeffs, 0.0, 10.0, t) for t in times])
y_expected = f(times)
with self.test_session() as sess:
y_actual = sess.run(y_fit)
self.assertAllClose(y_expected, y_actual)
# attempt interpolation outside bounds
y_invalid = odes._interp_evaluate(coeffs, 0.0, 10.0, 100.0)
with self.test_session() as sess:
with self.assertRaises(errors_impl.InvalidArgumentError):
sess.run(y_invalid)