async function rfft(x, a) {
    const op = await TensorOpRegistry.rfft;
    return await op({ x, a });
}
Computes the one dimensional Fourier transform of real-valued input.
Inspired by https://pytorch.org/docs/stable/generated/torch.fft.rfft.html
@param {Tensor} x the real input tensor
@param {Tensor} a The dimension along which to take the one dimensional real FFT.
@returns {Promise<Tensor>} the output tensor.