def test_nfft_inplace_2d(self):
a = numpy.random.random((self._size, )*2)
ft_nfft = numpy.empty(2, dtype="complex128")
nfft.nfft_inplace(a, [[self._coord_1d[self._2d_coord[0][0]], self._coord_1d[self._2d_coord[0][1]]],
[self._coord_1d[self._2d_coord[1][0]], self._coord_1d[self._2d_coord[1][1]]]], ft_nfft)
ft_fftw = numpy.fft.fftshift(numpy.fft.fft2(numpy.fft.fftshift(a)))
numpy.testing.assert_almost_equal(ft_nfft, ft_fftw[(self._2d_coord[0][0], self._2d_coord[1][0]), (self._2d_coord[0][1], self._2d_coord[1][1])])
def test_nfft_inplace_1d(self):
a = numpy.random.random(self._size)
ft_nfft = numpy.empty(self._size, dtype="complex128")
nfft.nfft_inplace(a, 1., self._coord_1d, ft_nfft)
ft_fftw = numpy.fft.fftshift(numpy.fft.fft(numpy.fft.fftshift(a)))
numpy.testing.assert_almost_equal(ft_nfft,
ft_fftw,
decimal=self._decimals)
def test_nfft_inplace_direct(self):
#a = numpy.random.random(self._size)
a = numpy.random.random((4, )*4)
#coordinates = -0.5+numpy.random.random(100)
number_of_points = 100.
coordinates = numpy.array(zip(-0.5 + numpy.random.random(number_of_points), -0.5 + numpy.random.random(number_of_points),
-0.5 + numpy.random.random(number_of_points), -0.5 + numpy.random.random(number_of_points)))
ft_nfft = numpy.empty(len(coordinates), dtype="complex128")
nfft.nfft_inplace(a, coordinates, ft_nfft, use_direct=False)
ft_nfft_direct = numpy.empty(len(coordinates), dtype="complex128")
nfft.nfft_inplace(a, coordinates, ft_nfft_direct, use_direct=True)
numpy.testing.assert_almost_equal(ft_nfft, ft_nfft_direct, decimal=3)
def test_nfft_4d(self):
size = 6
coord_1d = numpy.linspace(-0.5, 0.5-1./size, size)
a = numpy.random.random((size, )*4)
ft_nfft = numpy.empty(2, dtype="complex128")
nfft.nfft_inplace(a, [[coord_1d[self._4d_coord[0][0]], coord_1d[self._4d_coord[0][1]], coord_1d[self._4d_coord[0][2]], coord_1d[self._4d_coord[0][3]]],
[coord_1d[self._4d_coord[1][0]], coord_1d[self._4d_coord[1][1]], coord_1d[self._4d_coord[1][2]], coord_1d[self._4d_coord[1][3]]]],
ft_nfft)
ft_fftw = numpy.fft.fftshift(numpy.fft.fftn(numpy.fft.fftshift(a)))
numpy.testing.assert_almost_equal(ft_nfft, ft_fftw[(self._4d_coord[0][0], self._4d_coord[1][0]),
(self._4d_coord[0][1], self._4d_coord[1][1]),
(self._4d_coord[0][2], self._4d_coord[1][2]),
(self._4d_coord[0][3], self._4d_coord[1][3])])
def test_nfft_inplace_direct(self):
#a = numpy.random.random(self._size)
a = numpy.random.random((4, ) * 4)
#coordinates = -0.5+numpy.random.random(100)
number_of_points = 100
coordinates = numpy.array(
zip(-0.5 + numpy.random.random(number_of_points),
-0.5 + numpy.random.random(number_of_points),
-0.5 + numpy.random.random(number_of_points),
-0.5 + numpy.random.random(number_of_points)))
ft_nfft = numpy.empty(len(coordinates), dtype="complex128")
nfft.nfft_inplace(a, 1., coordinates, ft_nfft, use_direct=False)
ft_nfft_direct = numpy.empty(len(coordinates), dtype="complex128")
nfft.nfft_inplace(a, 1., coordinates, ft_nfft_direct, use_direct=True)
#we use lower precision since these are actually expected to differ
numpy.testing.assert_almost_equal(ft_nfft, ft_nfft_direct, decimal=2)
def test_nfft_inplace_1d(self):
a = numpy.random.random(self._size)
ft_nfft = numpy.empty(self._size, dtype="complex128")
nfft.nfft_inplace(a, self._coord_1d, ft_nfft)
ft_fftw = numpy.fft.fftshift(numpy.fft.fft(numpy.fft.fftshift(a)))
numpy.testing.assert_almost_equal(ft_nfft, ft_fftw, decimal=self._decimals)