Computes the one dimensional Fourier transform of real-valued input.
Arguments
- self
(Tensor) the real input tensor
- n
(int) Signal length. If given, the input will either be zero-padded or trimmed to this length before computing the real FFT.
- dim
(int, optional) – The dimension along which to take the one dimensional real FFT.
- norm
norm (str, optional) – Normalization mode. For the forward transform, these correspond to:
"forward" - normalize by 1/n
"backward" - no normalization
"ortho" - normalize by 1/sqrt(n) (making the FFT orthonormal) Calling the backward transform (
torch_fft_irfft()) with the same normalization mode will apply an overall normalization of 1/n between the two transforms. This is required to make irfft() the exact inverse. Default is "backward" (no normalization).
Details
The FFT of a real signal is Hermitian-symmetric, X[i] = conj(X[-i]) so the
output contains only the positive frequencies below the Nyquist frequency.
To compute the full output, use torch_fft_fft().
Examples
if (torch_is_installed()) {
t <- torch_arange(start = 0, end = 3)
torch_fft_rfft(t)
}
#> torch_tensor
#> ℹ Use `$real` or `$imag` to print the contents of this tensor.
#> [ CPUComplexFloatType{3} ]