sym_rfftn for ifftn
This is an ommission from the changes I made in my scipy PR: ifftn
for real input can be optimised in exactly the same way as with fftn
. You just need to take the complex conjugate of the 1D r2c transform before continuing to the remainging axes.
I suspect it's not a very common use case but it's not difficult to add. Alternatively, this could go into pocketfft itself as a forwards
argument to r2c
.