Hi !
No I haven’t solved this, I am still using the big matrix as the leaf, and I hope that the gradient is not computed for the zero values.
Right now, I am more interested in if the sparse API is going to be supplemented with more functions and autograd. That would solve the problem probably.
I could try to implement the C functions myself (like sparse matmul, and its gradient) and wrap them in Python like it is said to be possible here : https://github.com/pytorch/extension-ffi 9
I don’t know how long that is going to take me though…