chainer.Variable can be converted into a sparse matrix in e.g.
COO (Coordinate list) format.
A sparse matrix stores the same data as the original object but with a
different internal representation, optimized for efficient operations on
sparse data, i.e. data with many zero elements.
Following are a list of supported sparse matrix formats and utilities for
converting between a
chainer.Variable and these representations.
Please be aware that only certain functions accept sparse matrices as
inputs, such as
||A sparse matrix in COO format.|
||Returns a single or a batch of matrices in COO format.|