Stable release | 2.1.3
/ June 14, 2023 |
---|---|
Operating system | Cross-platform |
Available in | C, Fortran |
Type | Software library |
License | New BSD License |
Website | www.ssisc.org/lis/ |
Lis (Library of Iterative Solvers for linear systems, pronounced [lis]) is a scalable parallel software library for solving discretized linear equations and eigenvalue problems that mainly arise in the numerical solution of partial differential equations by using iterative methods.[1][2][3] Although it is designed for parallel computers, the library can be used without being conscious of parallel processing.
Lis provides facilities for:
A C program to solve the linear equation is written as follows:
#include <stdio.h>
#include "lis_config.h"
#include "lis.h"
LIS_INT main(LIS_INT argc, char* argv[])
{
LIS_MATRIX A;
LIS_VECTOR b, x;
LIS_SOLVER solver;
LIS_INT iter;
double time;
lis_initialize(&argc, &argv);
lis_matrix_create(LIS_COMM_WORLD, &A);
lis_vector_create(LIS_COMM_WORLD, &b);
lis_vector_create(LIS_COMM_WORLD, &x);
lis_input_matrix(A, argv[1]);
lis_input_vector(b, argv[2]);
lis_vector_duplicate(A, &x);
lis_solver_create(&solver);
lis_solver_set_optionC(solver);
lis_solve(A, b, x, solver);
lis_solver_get_iter(solver, &iter);
lis_solver_get_time(solver, &time);
printf("number of iterations = %d\n", iter);
printf("elapsed time = %e\n", time);
lis_output_vector(x, LIS_FMT_MM, argv[3]);
lis_solver_destroy(solver);
lis_matrix_destroy(A);
lis_vector_destroy(b);
lis_vector_destroy(x);
lis_finalize();
return 0;
}
The installation of Lis requires a C compiler. The Fortran interface requires a Fortran compiler, and the algebraic multigrid preconditioner requires a Fortran 90 compiler.[4] For parallel computing environments, an OpenMP or MPI library is required. Both the Matrix Market and Harwell-Boeing formats are supported to import and export user data.