Error with einsum in Equivariance plot about s2cnn

[SkirOwen]

I've found a temporary fix, that works for me:

If you have pytorch == 1.7.*:

• change all functions of the form pytorch.fft.____ to pytorch.Tensor.____

If pytorch >= 1.7 then follow:

• https://github.com/pytorch/pytorch/wiki/The-torch.fft-module-in-PyTorch-1.7

[mariogeiger]

I guess the error was introduced in #51 since I guessed the Fourier transform from pytorch changed the format of the output by a little.

I don't have the time to deep into this now. PR are welcome. In case you look for similar features (Fourier transform on the sphere) have a look at the project e3nn that is maintained.

[SkirOwen]

I've found this:
https://github.com/pytorch/pytorch/wiki/The-torch.fft-module-in-PyTorch-1.7