dask.array.fft.rfft2

dask.array.fft.rfft2(a, s=None, axes=None)

Wrapping of numpy.fft.rfft2

The axis along which the FFT is applied must have only one chunk. To change the array’s chunking use dask.Array.rechunk.

The numpy.fft.rfft2 docstring follows below:

Compute the 2-dimensional FFT of a real array.

Parameters
aarray

Input array, taken to be real.

ssequence of ints, optional

Shape of the FFT.

axessequence of ints, optional

Axes over which to compute the FFT.

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 real 2-D FFT.

See also

rfftn

Compute the N-dimensional discrete Fourier Transform for real input.

Notes

This is really just rfftn with different default behavior. For more details see rfftn.

Examples

>>> a = np.mgrid[:5, :5][0]  
>>> np.fft.rfft2(a)  
array([[ 50.  +0.j        ,   0.  +0.j        ,   0.  +0.j        ],
       [-12.5+17.20477401j,   0.  +0.j        ,   0.  +0.j        ],
       [-12.5 +4.0614962j ,   0.  +0.j        ,   0.  +0.j        ],
       [-12.5 -4.0614962j ,   0.  +0.j        ,   0.  +0.j        ],
       [-12.5-17.20477401j,   0.  +0.j        ,   0.  +0.j        ]])