rfft2

paddle.fft. rfft2 ( x, s=None, axes=(- 2, - 1), norm='backward', name=None ) [source]

The two dimensional FFT with real tensor input.

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

Parameters

  • x (Tensor) – Input tensor, taken to be real.

  • s (Sequence[int], optional) – Shape of the FFT.

  • axes (Sequence[int], optional) – Axes over which to compute the FFT.

  • norm (str, optional) –

    {“backward”, “ortho”, “forward”}, default is “backward”. Indicates which direction of the forward/backward pair of transforms is scaled and with what normalization factor. The details of three operations are shown below:

    • ”backward”: The factor of forward direction and backward direction are 1 and 1/n respectively;

    • ”forward”: The factor of forward direction and backward direction are 1/n and 1 respectively;

    • ”ortho”: The factor of forward direction and backword direction are both 1/sqrt(n).

    Where n is the multiplication of each element in s .

  • name (str, optional) – The default value is None. Normally there is no need for user to set this property. For more information, please refer to Name .

Returns

The result of the real 2-D FFT.

Return type

out(Tensor)

Examples:

import paddle
import numpy as np

x = paddle.to_tensor(np.mgrid[:5, :5][0].astype(np.float32))
print(paddle.fft.rfft2(x))
# Tensor(shape=[5, 3], dtype=complex64, place=CUDAPlace(0), stop_gradient=True,
#        [[ (50+0j)                                        ,  (1.1920928955078125e-07+0j)                    ,  0j                                             ],
#         [(-12.5+17.204774856567383j)                     , (-9.644234211236835e-08+7.006946134424652e-08j) ,  0j                                             ],
#         [(-12.500000953674316+4.061495304107666j)        , (3.6837697336977726e-08-1.1337477445749755e-07j),  0j                                             ],
#         [(-12.500000953674316-4.061495304107666j)        , (3.6837697336977726e-08+1.1337477445749755e-07j),  0j                                             ],
#         [(-12.5-17.204774856567383j)                     , (-9.644234211236835e-08-7.006946134424652e-08j) ,  0j                                             ]])