SPARSLAB Software

Introduction

This page is devoted to Sparslab software. Sparslab is a package which covers codes developed for the experimental parts of the papers written by Michele Benzi and Miroslav Tůma and some other collaborators and for some related projects. Most of these projects were partially supported by grants of the Grant Agency of the Academy of Sciences of the Czech Republic.

A substantial part of all the software are iterative solvers preconditioned by AINV, SAINV, RIF and others were concieved, made and tested by Michele Benzi and Miroslav Tůma. Most of the codes is written in a very conservative f90 and can be easily compiled. The development was motivated not by a need to provide a complete package covering some parts of numerical linear algebra but mainly by the need to test various algorithmic ideas in the field of preconditioned iterative solvers.

Currently available

Currently we present only a small fraction of the whole package as independent units with all dependencies. The codes are assembled from a large pool of various subroutines, functions and auxiliary routines written over the years. We concentrate on making available some of nontrivial implementations based on sparse data structures. In the future we assume to make the whole package available. The files are typically stored in DOS format and might be converted into the unix using the attached utility or by some other way. So far, no other documentation than that provided in the source codes is available.

Using the codes

The codes can be freely used for research purposes provided the Sparslab package is cited. Other use should be consulted at tuma(at)cs(dot)cas(dot)cz.

Preconditioners with MATLAB interfaces

These codes are first attepts to generate some basic preconditioners as mex-f90 sources with an corresponding m-file interface. The codes were tested only slightly up to now.

Right-looking RIF preconditioner and its MATLAB interface: RIF preconditioner for solving systems of linear algebraic equations with positive definite matrices rifmex.tar.gz

Right-looking RIF preconditioner for normal systems and its MATLAB interface: RIF code for solving normal equations avoiding explicit forming A'*A rifnrimex.tar.gz

Right-looking SAINV preconditioner and its MATLAB interface: right-looking SAINV preconditioner for MATLAB in f90, dll executable for Win XP sainvmex.tar.gz

Left-looking AINV preconditioner and its MATLAB interface: f90 code, dll executable for Win XP ainvlmex.tar.gz

ICAJ preconditioner (Incomplete Cholesky, Ajiz-Jennings strategy, and its MATLAB interface: code in f90, right-looking icajmex.tar.gz

Preconditioners in Fortran with Fortran drivers

SAINV for a symmetric and positive definite matrix and evaluation of x \approx inv(A)*b. Test driver with all its dependencies, simple makefile. sainvsr.tar.gz

RIF for a symmetric and positive definite matrix and evaluation of x \approx inv(A)*b. Test driver with all its dependencies, simple makefile. rifsr.tar.gz

RIF for solving normal equations (explicit) (right-looking RIF code in fixed format f90 covering a simple driver and the necessary subroutines) rifsrnre.tar.gz

RIF for solving normal equations without forming A^T*A (i.e., implicit) (right-looking RIF code in fixed format f90 covering a simple driver and the necessary subroutines) rifsrnri.tar.gz

All the following AISM codes were prepared jointly with Rafael Bru, Jose Marin and Jose Mas in fall 2005 and has been updated since.

Left-looking AISM preconditioner for a nonsymmetric matrix. Test driver with all its dependencies, simple makefile. aisml_subs.tar.gz

Left-looking infinite AISM preconditioner for a nonsymmetric matrix (having two triangular factors). Test driver with all its dependencies, simple makefile. aismli_subs.tar.gz

Left-looking AISM preconditioner for a nonsymmetric matrix with recurrences based on three vectors. Test driver with all its dependencies, simple makefile. aisml3v_subs.tar.gz

Right-looking AISM preconditioner for a nonsymmetric matrix (having two triangular factors). Test driver with all its dependencies, simple makefile. aismli_subs.tar.gz

Third party utilities

perl script for converting files from dos format into the unix one dos2unixpl

Acknowledgement

The project which initiated opening this web page was A1030103 of Grant Agency of the Academy of Sciences of the Czech Republic. This project was devoted to scalable solvers. The need to develop their substantial building blocks was one of our motivations for making the codes publicly available.

Currently, development of SPARSLAB codes is supported by the MWEB project from the program "Information Society" under No. 1ET400300415 of the Czech Republic.

Some specialized routines were developed for solving special augmented systems and were intended as production codes. Their current development is supported by the project of the Faculty of Mechatronics and Interdisciplinary Engineering Studies, Technical University in Liberec. We would appreciate any comments, bug reports etc. Note that this is really only an initial release of most of the interfaces wrapped around the codes.