def test_setup_windows_partitions_window(self):
nwindows = 5
window = (0, 1)
piecewisecheb = PiecewiseChebyshevApproximant(
np.sin, window_breakpoints=np.linspace(*window, nwindows + 1))
windows = piecewisecheb._setup_windows()
np.random.seed(72)
x = np.random.rand(101) * np.ptp(window) + window[0]
masks = [piecewisecheb._mask_window(x, w) for w in windows]
number_of_masks_contained = np.sum(masks, axis=0)
self.assertTrue(np.all(number_of_masks_contained == 1))
def test_call_accurately_approximates(self):
window = (0, 20)
piecewisecheb = PiecewiseChebyshevApproximant(
np.sin, window_breakpoints=np.linspace(*window, 21), degree=12)
x = np.linspace(window[0], window[1] - 0.1, 101)
true = np.sin(x)
approx = piecewisecheb(x)
self.assertTrue(np.allclose(true, approx, **TOLS))
def test_call_returns_correct_shape(self):
window = (0, 20)
piecewisecheb = PiecewiseChebyshevApproximant(
np.sin, window_breakpoints=np.linspace(*window, 6))
x = np.linspace(window[0], window[1] - 0.1, 101)
true = np.sin(x)
approx = piecewisecheb(x)
self.assertEqual(true.shape, approx.shape)
def test_call_raises_error_when_x_equal_to_max_window(self):
window = (0, 10)
piecewisecheb = PiecewiseChebyshevApproximant(
np.sin, window_breakpoints=np.linspace(*window, 6))
self.assertRaises(ValueError, piecewisecheb, window[1])
def test_dtype_on_complex(self):
piecewisecheb = PiecewiseChebyshevApproximant(
lambda x: np.exp(1j * x), window_breakpoints=np.linspace(0, 1, 6))
self.assertEqual(piecewisecheb._dtype.name, 'complex128')
def test_dtype_on_float(self):
piecewisecheb = PiecewiseChebyshevApproximant(
np.sin, window_breakpoints=np.linspace(0, 1, 6))
self.assertEqual(piecewisecheb._dtype.name, 'float64')
def test_setup_approximants_generates_approximants(self):
piecewisecheb = PiecewiseChebyshevApproximant(
np.sin, window_breakpoints=np.linspace(0, 1, 6))
approximants = piecewisecheb._setup_approximants()
for approximant in approximants:
self.assertTrue(isinstance(approximant, ChebyshevApproximant))
def test_setup_windows_splits_into_n_windows(self):
nwindows = 5
piecewisecheb = PiecewiseChebyshevApproximant(
np.sin, window_breakpoints=np.linspace(0, 1, nwindows + 1))
windows = piecewisecheb._setup_windows()
self.assertEqual(len(windows), nwindows)
def test_mask_window(self):
window = (0, 1)
x = np.linspace(0, 2, 101)
mask = PiecewiseChebyshevApproximant._mask_window(x, window)
self.assertLess(x[mask].max(), 1.0)
self.assertGreaterEqual(x[~mask].min(), 1.0)