ztichigo / learning-circuits

Learning Fast Algorithms for Linear Transforms Using Butterfly Factorizations

Code to accompany the paper Learning Fast Algorithms for Linear Transforms Using Butterfly Factorizations.

Requirements

Python 3.6+
PyTorch >=1.0
Numpy

Usage

• The module Butterfly in butterfly/butterfly.py can be used as a drop-in replacement for a nn.Linear layer. The files in butterfly directory are all that are needed for this use.

The butterfly multiplication is written in C++ and CUDA as PyTorch extension. To install it:

cd butterfly/factor_multiply
python setup.py install

Without the C++/CUDA version, butterfly multiplication is still usable, but is quite slow. The variable use_extension in butterfly/butterfly_multiply.py controls whether to use the C++/CUDA version or the pure PyTorch version.

For training, we've had better results with the Adam optimizer than SGD.

• The directory learning_transforms contains code to learn the transforms as presented in the paper. This directory is presently being developed and refactored.