pddrive1_abglobal.c

SuperLU 2.2版本。对大型、稀疏、非对称的线性系统的直接求解

/*
 * -- Distributed SuperLU routine (version 1.0) --
 * Lawrence Berkeley National Lab, Univ. of California Berkeley.
 * September 1, 1999
 *
 */

#include <math.h>
#include "superlu_ddefs.h"


main(int argc, char *argv[])
/*
 * Purpose
 * =======
 *
 * The driver program pddrive1_ABglobal.
 *
 * This example illustrates how to use pdgssvx_ABglobal to
 * solve systems with the same A but different right-hand side.
 * In this case, we factorize A only once in the first call to
 * pdgssvx_ABglobal, and reuse the following data structures
 * in the subsequent call to pdgssvx_ABglobal:
 *        ScalePermstruct  : DiagScale, R, C, perm_r, perm_c
 *        LUstruct         : Glu_persist, Llu
 * 
 * On an IBM SP, the program may be run by typing:
 *    poe pddrive1_ABglobal -r <proc rows> -c <proc columns> <input_matrix> -procs <p>
 *
 */
{
    superlu_options_t options;
    SuperLUStat_t stat;
    SuperMatrix A;
    ScalePermstruct_t ScalePermstruct;
    LUstruct_t LUstruct;
    gridinfo_t grid;
    double   *berr;
    double   *a, *b, *b1, *xtrue;
    int_t    *asub, *xa;
    int_t    i, j, m, n, nnz;
    int_t    nprow, npcol;
    int      iam, info, ldb, ldx, nrhs;
    char     trans[1];
    char     **cpp, c;
    FILE *fp, *fopen();
    extern int cpp_defs();

    nprow = 1;  /* Default process rows.      */
    npcol = 1;  /* Default process columns.   */
    nrhs = 1;   /* Number of right-hand side. */

    /* ------------------------------------------------------------
       INITIALIZE MPI ENVIRONMENT. 
       ------------------------------------------------------------*/
    MPI_Init( &argc, &argv );

    /* Parse command line argv[]. */
    for (cpp = argv+1; *cpp; ++cpp) {
	if ( **cpp == '-' ) {
	    c = *(*cpp+1);
	    ++cpp;
	    switch (c) {
	      case 'h':
		  printf("Options:\n");
		  printf("\t-r <int>: process rows    (default %d)\n", nprow);
		  printf("\t-c <int>: process columns (default %d)\n", npcol);
		  exit(0);
		  break;
	      case 'r': nprow = atoi(*cpp);
		        break;
	      case 'c': npcol = atoi(*cpp);
		        break;
	    }
	} else { /* Last arg is considered a filename */
	    if ( !(fp = fopen(*cpp, "r")) ) {
                ABORT("File does not exist");
            }
	    break;
	}
    }

    /* ------------------------------------------------------------
       INITIALIZE THE SUPERLU PROCESS GRID. 
       ------------------------------------------------------------*/
    superlu_gridinit(MPI_COMM_WORLD, nprow, npcol, &grid);

    /* Bail out if I do not belong in the grid. */
    iam = grid.iam;
    if ( iam >= nprow * npcol )
	goto out;
    
#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter main()");
#endif
    
    /* ------------------------------------------------------------
       PROCESS 0 READS THE MATRIX A, AND THEN BROADCASTS IT TO ALL
       THE OTHER PROCESSES.
       ------------------------------------------------------------*/
    if ( !iam ) {
	/* Print the CPP definitions. */
	cpp_defs();
	
	/* Read the matrix stored on disk in Harwell-Boeing format. */
	dreadhb_dist(iam, fp, &m, &n, &nnz, &a, &asub, &xa);
	
	printf("\tDimension\t%dx%d\t # nonzeros %d\n", m, n, nnz);
	printf("\tProcess grid\t%d X %d\n", grid.nprow, grid.npcol);

	/* Broadcast matrix A to the other PEs. */
	MPI_Bcast( &m,   1,   mpi_int_t,  0, grid.comm );
	MPI_Bcast( &n,   1,   mpi_int_t,  0, grid.comm );
	MPI_Bcast( &nnz, 1,   mpi_int_t,  0, grid.comm );
	MPI_Bcast( a,    nnz, MPI_DOUBLE, 0, grid.comm );
	MPI_Bcast( asub, nnz, mpi_int_t,  0, grid.comm );
	MPI_Bcast( xa,   n+1, mpi_int_t,  0, grid.comm );
    } else {
	/* Receive matrix A from PE 0. */
	MPI_Bcast( &m,   1,   mpi_int_t,  0, grid.comm );
	MPI_Bcast( &n,   1,   mpi_int_t,  0, grid.comm );
	MPI_Bcast( &nnz, 1,   mpi_int_t,  0, grid.comm );

	/* Allocate storage for compressed column representation. */
	dallocateA_dist(n, nnz, &a, &asub, &xa);

	MPI_Bcast( a,    nnz, MPI_DOUBLE, 0, grid.comm );
	MPI_Bcast( asub, nnz, mpi_int_t,  0, grid.comm );
	MPI_Bcast( xa,   n+1, mpi_int_t,  0, grid.comm );
    }
	
    /* Create compressed column matrix for A. */
    dCreate_CompCol_Matrix_dist(&A, m, n, nnz, a, asub, xa,
				SLU_NC, SLU_D, SLU_GE);

    /* Generate the exact solution and compute the right-hand side. */
    if ( !(b = doubleMalloc_dist(m * nrhs)) ) ABORT("Malloc fails for b[]");
    if ( !(b1 = doubleMalloc_dist(m * nrhs)) ) ABORT("Malloc fails for b1[]");
    if ( !(xtrue = doubleMalloc_dist(n*nrhs)) ) ABORT("Malloc fails for xtrue[]");
    *trans = 'N';
    ldx = n;
    ldb = m;
    dGenXtrue_dist(n, nrhs, xtrue, ldx);
    dFillRHS_dist(trans, nrhs, xtrue, ldx, &A, b, ldb);
    for (j = 0; j < nrhs; ++j)
	for (i = 0; i < m; ++i) b1[i+j*ldb] = b[i+j*ldb];

    if ( !(berr = doubleMalloc_dist(nrhs)) )
	ABORT("Malloc fails for berr[].");

    /* ------------------------------------------------------------
       WE SOLVE THE LINEAR SYSTEM FOR THE FIRST TIME.
       ------------------------------------------------------------*/

    /* Set the default input options:
        options.Fact = DOFACT;
        options.Equil = YES;
        options.ColPerm = MMD_AT_PLUS_A;
        options.RowPerm = LargeDiag;
        options.ReplaceTinyPivot = YES;
        options.Trans = NOTRANS;
        options.IterRefine = DOUBLE;
        options.SolveInitialized = NO;
        options.RefineInitialized = NO;
        options.PrintStat = YES;
     */
    set_default_options_dist(&options);

    /* Initialize ScalePermstruct and LUstruct. */
    ScalePermstructInit(m, n, &ScalePermstruct);
    LUstructInit(m, n, &LUstruct);

    /* Initialize the statistics variables. */
    PStatInit(&stat);

    /* Call the linear equation solver: factorize and solve. */
    pdgssvx_ABglobal(&options, &A, &ScalePermstruct, b, ldb, nrhs, &grid,
		     &LUstruct, berr, &stat, &info);

    /* Check the accuracy of the solution. */
    if ( !iam ) {
	dinf_norm_error_dist(n, nrhs, b, ldb, xtrue, ldx, &grid);
    }

    PStatPrint(&options, &stat, &grid);        /* Print the statistics. */
    PStatFree(&stat);

    /* ------------------------------------------------------------
       NOW WE SOLVE ANOTHER SYSTEM WITH THE SAME A BUT DIFFERENT
       RIGHT-HAND SIDE,  WE WILL USE THE EXISTING L AND U FACTORS IN
       LUSTRUCT OBTAINED FROM A PREVIOUS FATORIZATION.
       ------------------------------------------------------------*/
    options.Fact = FACTORED; /* Indicate the factored form of A is supplied. */
    PStatInit(&stat); /* Initialize the statistics variables. */

    pdgssvx_ABglobal(&options, &A, &ScalePermstruct, b1, ldb, nrhs, &grid,
		     &LUstruct, berr, &stat, &info);

    /* Check the accuracy of the solution. */
    if ( !iam ) {
	printf("Solve the system with a different B.\n");
	dinf_norm_error_dist(n, nrhs, b1, ldb, xtrue, ldx, &grid);
    }

    /* Print the statistics. */
    PStatPrint(&options, &stat, &grid);

    /* ------------------------------------------------------------
       DEALLOCATE STORAGE.
       ------------------------------------------------------------*/
    PStatFree(&stat);
    Destroy_CompCol_Matrix_dist(&A);
    Destroy_LU(n, &grid, &LUstruct);
    ScalePermstructFree(&ScalePermstruct);
    LUstructFree(&LUstruct);
    SUPERLU_FREE(b);
    SUPERLU_FREE(b1);
    SUPERLU_FREE(xtrue);
    SUPERLU_FREE(berr);

    /* ------------------------------------------------------------
       RELEASE THE SUPERLU PROCESS GRID.
       ------------------------------------------------------------*/
out:
    superlu_gridexit(&grid);

    /* ------------------------------------------------------------
       TERMINATES THE MPI EXECUTION ENVIRONMENT.
       ------------------------------------------------------------*/
    MPI_Finalize();

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Exit main()");
#endif

}


int cpp_defs()
{
    printf(".. CPP definitions:\n");
#if ( PRNTlevel>=1 )
    printf("\tPRNTlevel = %d\n", PRNTlevel);
#endif
#if ( DEBUGlevel>=1 )
    printf("\tDEBUGlevel = %d\n", DEBUGlevel);
#endif
#if ( PROFlevel>=1 )
    printf("\tPROFlevel = %d\n", PROFlevel);
#endif
#if ( StaticPivot>=1 )
    printf("\tStaticPivot = %d\n", StaticPivot);
#endif
    printf("....\n");
    return 0;
}