The library for utilization of Minimal Quadtree format for storing very large sparse matrices.
Please see the paper referenced below for the description of a problem.
Corresponding papers: Tree-based Space Efficient Formats for Storing the Structure of Sparse Matrices (I. Šimeček, D. Langr, P. Tvrdík), In Scalable Computing: Practice and Experience, volume 15, 2014.
Space Efficient Formats for Structure of Sparse Matrices Based on Tree Structures (I. Šimeček, Daniel Langr, Pavel Tvrdík...