def test_indexing_error(self):
""" Test that fft2freq correctly raises ValueError for invalid indexing. """
extent_x = np.linspace(0, 1)
extent_y = np.linspace(3, 4, num=47)
with self.assertRaises(ValueError):
fft2freq([1, 2], [1, 2], indexing="ab")
def test_shape():
""" Test that the output from fft2freq has the same shape as the input. """
extent_x = np.linspace(0, 1)
extent_y = np.linspace(3, 4, num=47)
for indexing in {"ij", "xy"}:
x, y = np.meshgrid(extent_x, extent_y, indexing=indexing)
kx, ky = fft2freq(x, y, indexing=indexing)
assert x.shape == kx.shape
assert y.shape == ky.shape
def test_shape(self):
""" Test that the output from fft2freq has the same shape as the input. """
extent_x = np.linspace(0, 1)
extent_y = np.linspace(3, 4, num=47)
for indexing in {"ij", "xy"}:
with self.subTest("Indexing {}".format(indexing)):
x, y = np.meshgrid(extent_x, extent_y, indexing=indexing)
kx, ky = fft2freq(x, y, indexing=indexing)
self.assertTupleEqual(x.shape, kx.shape)
self.assertTupleEqual(y.shape, ky.shape)
def test_vs_fftfreq():
""" Test that the results make sense with respect to 1D case """
extent_x = np.arange(0, 10, step=0.1)
extent_y = np.arange(3, 4, step=0.1)
for indexing in {"ij", "xy"}:
x, y = np.meshgrid(extent_x, extent_y, indexing=indexing)
kx, ky = fft2freq(x, y, indexing=indexing)
# same array creates from the 1d case
kx_1d = np.fft.fftfreq(len(extent_x), d=0.1)
ky_1d = np.fft.fftfreq(len(extent_y), d=0.1)
kx2, ky2 = np.meshgrid(kx_1d, ky_1d, indexing=indexing)
assert np.allclose(kx, kx2)
assert np.allclose(ky, ky2)