numpy.fft.irfft2¶

fft.irfft2(a, s=None, axes=(- 2, - 1), norm=None)[source]¶

Computes the inverse of rfft2.

Parameters

aarray_like: The input array
ssequence of ints, optional: Shape of the real output to the inverse FFT.
axessequence of ints, optional: The axes over which to compute the inverse fft. Default is the last two axes.
norm{“backward”, “ortho”, “forward”}, optional: New in version 1.10.0.

Normalization mode (see numpy.fft). Default is “backward”. Indicates which direction of the forward/backward pair of transforms is scaled and with what normalization factor.

New in version 1.20.0: The “backward”, “forward” values were added.

Returns

outndarray: The result of the inverse real 2-D FFT.

See also

rfft2: The forward two-dimensional FFT of real input, of which irfft2 is the inverse.
rfft: The one-dimensional FFT for real input.
irfft: The inverse of the one-dimensional FFT of real input.
irfftn: Compute the inverse of the N-dimensional FFT of real input.

Notes

This is really irfftn with different defaults. For more details see irfftn.

Examples

>>> a = np.mgrid[:5, :5][0]
>>> A = np.fft.rfft2(a)
>>> np.fft.irfft2(A, s=a.shape)
array([[0., 0., 0., 0., 0.],
       [1., 1., 1., 1., 1.],
       [2., 2., 2., 2., 2.],
       [3., 3., 3., 3., 3.],
       [4., 4., 4., 4., 4.]])

numpy.fft.rfft2 numpy.fft.rfftn