transformed dimensions. If given, each dimension "dim[i]" will
        either be zero-padded or trimmed to the length "s[i]" before
        computing the FFT. If a length "-1" is specified, no padding
        is done in that dimension. Default: "s = [input.size(d) for d
        in dim]"
  * **dim** (*Tuple**[**int**]**, **optional*) -- Dimensions to be
    transformed. Default: last two dimensions.

  * **norm** (*str**, **optional*) --

    Normalization mode. For the forward transform ("fft2()"),
    these correspond to:

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

    * ""backward"" - no normalization

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

    Where "n = prod(s)" is the logical FFT size. Calling the
    backward transform ("ifft2()") with the same normalization
    mode will apply an overall normalization of "1/n" between the
    two transforms. This is required to make "ifft2()" the exact
    inverse.
