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.]])