2: static char help[] = "Tests external direct solvers. Simplified from ex125.c\n\
  3: Example: mpiexec -n <np> ./ex130 -f <matrix binary file> -mat_solver_package 1 -mat_superlu_equil \n\n";

  5: #include <petscmat.h>

  9: int main(int argc,char **args)
 10: {
 11:   Mat            A,F;
 12:   Vec            u,x,b;
 14:   PetscMPIInt    rank,size;
 15:   PetscInt       m,n,nfact,ipack=0;
 16:   PetscReal      norm,tol=1.e-12,Anorm;
 17:   IS             perm,iperm;
 18:   MatFactorInfo  info;
 19:   PetscBool      flg,testMatSolve=PETSC_TRUE;
 20:   PetscViewer    fd;              /* viewer */
 21:   char           file[PETSC_MAX_PATH_LEN]; /* input file name */

 23:   PetscInitialize(&argc,&args,(char*)0,help);
 24:   MPI_Comm_rank(PETSC_COMM_WORLD, &rank);
 25:   MPI_Comm_size(PETSC_COMM_WORLD, &size);

 27:   /* Determine file from which we read the matrix A */
 28:   PetscOptionsGetString(NULL,NULL,"-f",file,PETSC_MAX_PATH_LEN,&flg);
 29:   if (!flg) SETERRQ(PETSC_COMM_WORLD,1,"Must indicate binary file with the -f option");

 31:   /* Load matrix A */
 32:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&fd);
 33:   MatCreate(PETSC_COMM_WORLD,&A);
 34:   MatLoad(A,fd);
 35:   VecCreate(PETSC_COMM_WORLD,&b);
 36:   VecLoad(b,fd);
 37:   PetscViewerDestroy(&fd);
 38:   MatGetLocalSize(A,&m,&n);
 39:   if (m != n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ, "This example is not intended for rectangular matrices (%d, %d)", m, n);
 40:   MatNorm(A,NORM_INFINITY,&Anorm);

 42:   /* Create vectors */
 43:   VecDuplicate(b,&x);
 44:   VecDuplicate(x,&u); /* save the true solution */

 46:   /* Test LU Factorization */
 47:   MatGetOrdering(A,MATORDERINGNATURAL,&perm,&iperm);

 49:   PetscOptionsGetInt(NULL,NULL,"-mat_solver_package",&ipack,NULL);
 50:   switch (ipack) {
 51:   case 1:
 52: #if defined(PETSC_HAVE_SUPERLU)
 53:     if (!rank) printf(" SUPERLU LU:\n");
 54:     MatGetFactor(A,MATSOLVERSUPERLU,MAT_FACTOR_LU,&F);
 55:     break;
 56: #endif
 57:   case 2:
 58: #if defined(PETSC_HAVE_MUMPS)
 59:     if (!rank) printf(" MUMPS LU:\n");
 60:     MatGetFactor(A,MATSOLVERMUMPS,MAT_FACTOR_LU,&F);
 61:     {
 62:       /* test mumps options */
 63:       PetscInt icntl_7 = 5;
 64:       MatMumpsSetIcntl(F,7,icntl_7);
 65:     }
 66:     break;
 67: #endif
 68:   default:
 69:     if (!rank) printf(" PETSC LU:\n");
 70:     MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_LU,&F);
 71:   }

 73:   info.fill = 5.0;
 74:   MatLUFactorSymbolic(F,A,perm,iperm,&info);

 76:   for (nfact = 0; nfact < 1; nfact++) {
 77:     if (!rank) printf(" %d-the LU numfactorization \n",nfact);
 78:     MatLUFactorNumeric(F,A,&info);

 80:     /* Test MatSolve() */
 81:     if (testMatSolve) {
 82:       MatSolve(F,b,x);

 84:       /* Check the residual */
 85:       MatMult(A,x,u);
 86:       VecAXPY(u,-1.0,b);
 87:       VecNorm(u,NORM_INFINITY,&norm);
 88:       if (norm > tol) {
 89:         if (!rank) {
 90:           PetscPrintf(PETSC_COMM_SELF,"MatSolve: rel residual %g/%g = %g, LU numfact %d\n",norm,Anorm,norm/Anorm,nfact);
 91:         }
 92:       }
 93:     }
 94:   }

 96:   /* Free data structures */
 97:   MatDestroy(&A);
 98:   MatDestroy(&F);
 99:   ISDestroy(&perm);
100:   ISDestroy(&iperm);
101:   VecDestroy(&x);
102:   VecDestroy(&b);
103:   VecDestroy(&u);
104:   PetscFinalize();
105:   return 0;
106: }