152 lines
6.5 KiB
Python
152 lines
6.5 KiB
Python
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import numpy
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from numpy import fft
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from numpy.testing import (assert_almost_equal, assert_array_almost_equal,
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assert_equal)
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import pytest
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from scipy import ndimage
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class TestNdimageFourier:
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@pytest.mark.parametrize('shape', [(32, 16), (31, 15), (1, 10)])
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@pytest.mark.parametrize('dtype, dec',
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[(numpy.float32, 6), (numpy.float64, 14)])
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def test_fourier_gaussian_real01(self, shape, dtype, dec):
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a = numpy.zeros(shape, dtype)
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a[0, 0] = 1.0
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a = fft.rfft(a, shape[0], 0)
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a = fft.fft(a, shape[1], 1)
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a = ndimage.fourier_gaussian(a, [5.0, 2.5], shape[0], 0)
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a = fft.ifft(a, shape[1], 1)
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a = fft.irfft(a, shape[0], 0)
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assert_almost_equal(ndimage.sum(a), 1, decimal=dec)
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@pytest.mark.parametrize('shape', [(32, 16), (31, 15)])
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@pytest.mark.parametrize('dtype, dec',
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[(numpy.complex64, 6), (numpy.complex128, 14)])
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def test_fourier_gaussian_complex01(self, shape, dtype, dec):
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a = numpy.zeros(shape, dtype)
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a[0, 0] = 1.0
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a = fft.fft(a, shape[0], 0)
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a = fft.fft(a, shape[1], 1)
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a = ndimage.fourier_gaussian(a, [5.0, 2.5], -1, 0)
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a = fft.ifft(a, shape[1], 1)
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a = fft.ifft(a, shape[0], 0)
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assert_almost_equal(ndimage.sum(a.real), 1.0, decimal=dec)
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@pytest.mark.parametrize('shape', [(32, 16), (31, 15), (1, 10)])
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@pytest.mark.parametrize('dtype, dec',
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[(numpy.float32, 6), (numpy.float64, 14)])
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def test_fourier_uniform_real01(self, shape, dtype, dec):
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a = numpy.zeros(shape, dtype)
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a[0, 0] = 1.0
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a = fft.rfft(a, shape[0], 0)
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a = fft.fft(a, shape[1], 1)
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a = ndimage.fourier_uniform(a, [5.0, 2.5], shape[0], 0)
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a = fft.ifft(a, shape[1], 1)
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a = fft.irfft(a, shape[0], 0)
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assert_almost_equal(ndimage.sum(a), 1.0, decimal=dec)
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@pytest.mark.parametrize('shape', [(32, 16), (31, 15)])
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@pytest.mark.parametrize('dtype, dec',
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[(numpy.complex64, 6), (numpy.complex128, 14)])
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def test_fourier_uniform_complex01(self, shape, dtype, dec):
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a = numpy.zeros(shape, dtype)
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a[0, 0] = 1.0
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a = fft.fft(a, shape[0], 0)
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a = fft.fft(a, shape[1], 1)
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a = ndimage.fourier_uniform(a, [5.0, 2.5], -1, 0)
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a = fft.ifft(a, shape[1], 1)
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a = fft.ifft(a, shape[0], 0)
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assert_almost_equal(ndimage.sum(a.real), 1.0, decimal=dec)
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@pytest.mark.parametrize('shape', [(32, 16), (31, 15)])
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@pytest.mark.parametrize('dtype, dec',
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[(numpy.float32, 4), (numpy.float64, 11)])
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def test_fourier_shift_real01(self, shape, dtype, dec):
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expected = numpy.arange(shape[0] * shape[1], dtype=dtype)
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expected.shape = shape
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a = fft.rfft(expected, shape[0], 0)
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a = fft.fft(a, shape[1], 1)
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a = ndimage.fourier_shift(a, [1, 1], shape[0], 0)
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a = fft.ifft(a, shape[1], 1)
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a = fft.irfft(a, shape[0], 0)
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assert_array_almost_equal(a[1:, 1:], expected[:-1, :-1],
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decimal=dec)
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assert_array_almost_equal(a.imag, numpy.zeros(shape),
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decimal=dec)
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@pytest.mark.parametrize('shape', [(32, 16), (31, 15)])
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@pytest.mark.parametrize('dtype, dec',
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[(numpy.complex64, 4), (numpy.complex128, 11)])
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def test_fourier_shift_complex01(self, shape, dtype, dec):
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expected = numpy.arange(shape[0] * shape[1], dtype=dtype)
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expected.shape = shape
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a = fft.fft(expected, shape[0], 0)
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a = fft.fft(a, shape[1], 1)
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a = ndimage.fourier_shift(a, [1, 1], -1, 0)
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a = fft.ifft(a, shape[1], 1)
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a = fft.ifft(a, shape[0], 0)
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assert_array_almost_equal(a.real[1:, 1:], expected[:-1, :-1],
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decimal=dec)
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assert_array_almost_equal(a.imag, numpy.zeros(shape),
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decimal=dec)
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@pytest.mark.parametrize('shape', [(32, 16), (31, 15), (1, 10)])
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@pytest.mark.parametrize('dtype, dec',
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[(numpy.float32, 5), (numpy.float64, 14)])
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def test_fourier_ellipsoid_real01(self, shape, dtype, dec):
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a = numpy.zeros(shape, dtype)
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a[0, 0] = 1.0
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a = fft.rfft(a, shape[0], 0)
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a = fft.fft(a, shape[1], 1)
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a = ndimage.fourier_ellipsoid(a, [5.0, 2.5],
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shape[0], 0)
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a = fft.ifft(a, shape[1], 1)
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a = fft.irfft(a, shape[0], 0)
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assert_almost_equal(ndimage.sum(a), 1.0, decimal=dec)
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@pytest.mark.parametrize('shape', [(32, 16), (31, 15)])
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@pytest.mark.parametrize('dtype, dec',
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[(numpy.complex64, 5), (numpy.complex128, 14)])
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def test_fourier_ellipsoid_complex01(self, shape, dtype, dec):
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a = numpy.zeros(shape, dtype)
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a[0, 0] = 1.0
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a = fft.fft(a, shape[0], 0)
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a = fft.fft(a, shape[1], 1)
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a = ndimage.fourier_ellipsoid(a, [5.0, 2.5], -1, 0)
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a = fft.ifft(a, shape[1], 1)
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a = fft.ifft(a, shape[0], 0)
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assert_almost_equal(ndimage.sum(a.real), 1.0, decimal=dec)
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def test_fourier_ellipsoid_unimplemented_ndim(self):
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# arrays with ndim > 3 raise NotImplementedError
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x = numpy.ones((4, 6, 8, 10), dtype=numpy.complex128)
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with pytest.raises(NotImplementedError):
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ndimage.fourier_ellipsoid(x, 3)
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def test_fourier_ellipsoid_1d_complex(self):
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# expected result of 1d ellipsoid is the same as for fourier_uniform
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for shape in [(32, ), (31, )]:
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for type_, dec in zip([numpy.complex64, numpy.complex128],
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[5, 14]):
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x = numpy.ones(shape, dtype=type_)
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a = ndimage.fourier_ellipsoid(x, 5, -1, 0)
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b = ndimage.fourier_uniform(x, 5, -1, 0)
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assert_array_almost_equal(a, b, decimal=dec)
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@pytest.mark.parametrize('shape', [(0, ), (0, 10), (10, 0)])
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@pytest.mark.parametrize('dtype',
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[numpy.float32, numpy.float64,
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numpy.complex64, numpy.complex128])
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@pytest.mark.parametrize('test_func',
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[ndimage.fourier_ellipsoid,
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ndimage.fourier_gaussian,
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ndimage.fourier_uniform])
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def test_fourier_zero_length_dims(self, shape, dtype, test_func):
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a = numpy.ones(shape, dtype)
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b = test_func(a, 3)
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assert_equal(a, b)
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