# 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

# 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                                             ]])
```