simple.c File Reference

A simple example that reads the matrix and then runs pastix in one call. More...

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Detailed Description

A simple example that reads the matrix and then runs pastix in one call.

Copyright

2015-2023 Bordeaux INP, CNRS (LaBRI UMR 5800), Inria, Univ. Bordeaux. All rights reserved.

Version

6.3.2

Author

Gregoire Pichon

Mathieu Faverge

Matias Hastaran

Pierre Ramet

Theophile Terraz

Tony Delarue

Alycia Lisito

Date

2023-07-21

  /
#include <pastix.h>
#include <spm.h>
 
int main (int argc, char **argv)
{
    pastix_data_t  *pastix_data = NULL; /*< Pointer to the storage structure required by pastix */
    pastix_int_t    iparm[IPARM_SIZE];  /*< Integer in/out parameters for pastix                */
    double          dparm[DPARM_SIZE];  /*< Floating in/out parameters for pastix               */
    spm_driver_t    driver;
    char           *filename = NULL;
    spmatrix_t     *spm, spm2;
    void           *x, *b, *x0 = NULL;
    size_t          size;
    int             check   = 1;
    int             scatter = 0;
    int             nrhs    = 1;
    int             rc      = 0;
 
    /**
     * Initialize parameters to default values
     */
    pastixInitParam( iparm, dparm );
 
    /**
     * Get options from command line
     */
    pastixGetOptions( argc, argv,
                      iparm, dparm,
                      &check, &scatter, &driver, &filename );
 
    /**
     * Startup PaStiX
     */
    pastixInit( &pastix_data, MPI_COMM_WORLD, iparm, dparm );
 
    /**
     * Read the sparse matrix with the driver
     */
    spm = malloc( sizeof( spmatrix_t ) );
    if ( scatter ) {
        rc = spmReadDriverDist( driver, filename, spm, MPI_COMM_WORLD );
    }
    else {
        rc = spmReadDriver( driver, filename, spm );
    }
    free( filename );
    if ( rc != SPM_SUCCESS ) {
        pastixFinalize( &pastix_data );
        return rc;
    }
 
    spmPrintInfo( spm, stdout );
 
    rc = spmCheckAndCorrect( spm, &spm2 );
    if ( rc != 0 ) {
        spmExit( spm );
        *spm = spm2;
        rc = 0;
    }
 
    /**
     * Generate a Fake values array if needed for the numerical part
     */
    if ( spm->flttype == SpmPattern ) {
        spmGenFakeValues( spm );
    }
 
    /**
     * Perform ordering, symbolic factorization, and analyze steps
     */
    pastix_task_analyze( pastix_data, spm );
 
    /**
     * Normalize A matrix (optional, but recommended for low-rank functionality)
     */
    double normA = spmNorm( SpmFrobeniusNorm, spm );
    spmScal( 1./normA, spm );
 
    /**
     * Perform the numerical factorization
     */
    pastix_task_numfact( pastix_data, spm );
 
    /**
     * Generates the b and x vector such that A * x = b
     * Compute the norms of the initial vectors if checking purpose.
     */
    size = pastix_size_of( spm->flttype ) * spm->nexp * nrhs;
    x = malloc( size );
    b = malloc( size );
 
    if ( check )
    {
        if ( check > 1 ) {
            x0 = malloc( size );
        }
        spmGenRHS( SpmRhsRndX, nrhs, spm, x0, spm->nexp, b, spm->nexp );
        memcpy( x, b, size );
    }
    else {
        spmGenRHS( SpmRhsRndB, nrhs, spm, NULL, spm->nexp, x, spm->nexp );
 
        /* Apply also normalization to b vectors */
        spmScalMat( 1./normA, spm, nrhs, b, spm->nexp );
 
        /* Save b for refinement */
        memcpy( b, x, size );
    }
 
    /**
     * Solve the linear system (and perform the optional refinement)
     */
    pastix_task_solve( pastix_data, spm->nexp, nrhs, x, spm->nexp );
    pastix_task_refine( pastix_data, spm->nexp, nrhs, b, spm->nexp, x, spm->nexp );
 
    if ( check )
    {
        rc = spmCheckAxb( dparm[DPARM_EPSILON_REFINEMENT], nrhs, spm, x0, spm->nexp, b, spm->nexp, x, spm->nexp );
 
        if ( x0 ) {
            free( x0 );
        }
    }
 
    spmExit( spm );
    free( spm );
    free( x );
    free( b );
    pastixFinalize( &pastix_data );
 
    return rc;
}
 
/**
 * 

Definition in file simple.c.