compressed dimension. Default: all dimensions, or the last
        "len(s)" dimensions if "s" is given.
  * **norm** (*str**, **optional*) --

    Normalization mode. For the backward transform ("irfftn()"),
    these correspond to:

    * ""forward"" - no normalization

    * ""backward"" - normalize by "1/n"

    * ""ortho"" - normalize by "1/sqrt(n)" (making the real IFFT
      orthonormal)

    Where "n = prod(s)" is the logical IFFT size. Calling the
    forward transform ("rfftn()") with the same normalization mode
    will apply an overall normalization of "1/n" between the two
    transforms. This is required to make "irfftn()" the exact
    inverse.

    Default is ""backward"" (normalize by "1/n").

Keyword Arguments:
      out (Tensor, optional) -- the output tensor.
-[ Example ]-



t = torch.rand(10, 9)
T = torch.fft.rfftn(t)



Without specifying the output length to "irfft()", the output will