On the use of low rank approximations for sparse direct solvers

In this talk, we describe a preliminary fast direct solver using HODLR library to compress large blocks appearing in the symbolic structure of the PaStiX sparse direct solver. We will present our general strategy before analyzing the practical gains in terms of memory and floating point operations with respect to a theoretical study of the problem. Finally, we will discuss the impact of reordering technic to enhance the low-rank compression.

Conference paper