mars.tensor.fft.ifftshift#

mars.tensor.fft.ifftshift(x, axes=None)[source]#

The inverse of fftshift. Although identical for even-length x, the functions differ by one sample for odd-length x.

Parameters

x (array_like) – Input tensor.
axes (int or shape tuple, optional) – Axes over which to calculate. Defaults to None, which shifts all axes.

Returns

y – The shifted tensor.

Return type

Tensor

See also

fftshift: Shift zero-frequency component to the center of the spectrum.

Examples

>>> import mars.tensor as mt

>>> freqs = mt.fft.fftfreq(9, d=1./9).reshape(3, 3)
>>> freqs.execute()
array([[ 0.,  1.,  2.],
       [ 3.,  4., -4.],
       [-3., -2., -1.]])
>>> mt.fft.ifftshift(mt.fft.fftshift(freqs)).execute()
array([[ 0.,  1.,  2.],
       [ 3.,  4., -4.],
       [-3., -2., -1.]])