# tf.signal.rfft

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| [![](https://www.tensorflow.org/images/GitHub-Mark-32px.png) View source on GitHub](https://github.com/tensorflow/tensorflow/blob/v2.13.1/tensorflow/python/ops/signal/fft_ops.py#L115-L141) |

Real-valued fast Fourier transform.

#### View aliases


**Compat aliases for migration**

See
[Migration guide](https://www.tensorflow.org/guide/migrate) for
more details.

[`tf.compat.v1.signal.rfft`](https://www.tensorflow.org/api_docs/python/tf/signal/rfft), [`tf.compat.v1.spectral.rfft`](https://www.tensorflow.org/api_docs/python/tf/signal/rfft)

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    tf.signal.rfft(
        input_tensor, fft_length=None, name=None
    )

Computes the 1-dimensional discrete Fourier transform of a real-valued signal
over the inner-most dimension of `input`.

Since the DFT of a real signal is Hermitian-symmetric, `RFFT` only returns the
`fft_length / 2 + 1` unique components of the FFT: the zero-frequency term,
followed by the `fft_length / 2` positive-frequency terms.

Along the axis `RFFT` is computed on, if `fft_length` is smaller than the
corresponding dimension of `input`, the dimension is cropped. If it is larger,
the dimension is padded with zeros.

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| ## Args ||
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| `input` | A `Tensor`. Must be one of the following types: `float32`, `float64`. A float32 tensor. |
| `fft_length` | A `Tensor` of type `int32`. An int32 tensor of shape \[1\]. The FFT length. |
| `name` | A name for the operation (optional). |

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| ## Returns ||
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| A `Tensor` of type `Tcomplex`. ||

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