STRUMPACK - STRUctured Matrix PACKage - is a software
library providing linear algebra routines and linear
system solvers for sparse and for dense rank-structured
linear systems. Many large dense matrices are rank
structured, meaning they exhibit some kind of low-rank
property, for instance in hierarchically defined
sub-blocks. In sparse direct solvers based on LU
factorization, the LU factors can often also be
approximated well using rank-structured matrix
compression, leading to robust preconditioners. The
sparse solver in STRUMPACK can also be used as an exact
direct solver, in which case it functions similarly as
or Superlu_Dist. The
STRUMPACK sparse direct solver delivers good performance
and distributed memory scalability and provides
excellent CUDA support.
Currently, STRUMPACK has support for the Hierarchically Semi-Separable (HSS), Block Low Rank (BLR), Hierachically Off-Diagonal Low Rank (HODLR), Butterfly and Hierarchically Off-Diagonal Butterfly (HODBF) rank-structured matrix formats. Such matrices appear in many applications, e.g., the Boundary Element Method for discretization of integral equations, structured matrices like Toeplitz and Cauchy, kernel and covariance matrices etc. In the LU factorization of sparse linear systems arising from the discretization of partial differential equations, the fill-in in the triangular factors often has low-rank structure. Hence, the sparse linear solve algorithms in STRUMPACK exploit the different dense rank-structured matrix formats to compress the fill-in. This leads to purely algebraic, fast and scalable (both with problem size and compute cores) approximate direct solvers or preconditioners. These preconditioners are mostly aimed at large sparse linear systems which result from the discretization of a partial differential equation, but are not limited to any particular type of problem. STRUMPACK also provides preconditioned GMRES and BiCGStab iterative solvers.
Apart from rank-structured compression, the STRUMPACK sparse solver also support compression of the factors using the ZFP library, a general purpose compression algorithm tuned for floating point data. This can be used with a specified precision, or with lossless compression.
The HODLR and Butterfly functionality in STRUMPACK is implemented through interfaces to the ButterflyPACK package.
The software is released under a BSD-style license.
The current development version of STRUMPACK is available on GitHub. You can always contact us if you have questions, bug-reports, requests, etc.Developers