numpy.fft.rfft2#
- fft.rfft2(a, s=None, axes=(-2, -1), norm=None, out=None)[source]#
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.
Changed in version 2.0: If it is
-1
, the whole input is used (no padding/trimming).Deprecated since version 2.0: If s is not
None
, axes must not beNone
either.Deprecated since version 2.0: s must contain only
int
s, notNone
values.None
values currently mean that the default value forn
is used in the corresponding 1-D transform, but this behaviour is deprecated.- axessequence of ints, optional
Axes over which to compute the FFT. Default:
(-2, -1)
.Deprecated since version 2.0: If s is specified, the corresponding axes to be transformed must not be
None
.- 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.
- outcomplex ndarray, optional
If provided, the result will be placed in this array. It should be of the appropriate shape and dtype for the last inverse transform. incompatible with passing in all but the trivial
s
).New in version 2.0.0.
- 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 seerfftn
.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 ]])