Date: 2021-02-01T14:42:12+00:00

Actual source code: test8.c
slepc-3.14.2 2021-02-01
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2020, Universitat Politecnica de Valencia, Spain

      6:    This file is part of SLEPc.
      7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
      8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      9: */

     11: static char help[] = "Test interface functions of polynomial JD.\n\n"
     12:   "This is based on ex16.c. The command line options are:\n"
     13:   "  -n <n>, where <n> = number of grid subdivisions in x dimension.\n"
     14:   "  -m <m>, where <m> = number of grid subdivisions in y dimension.\n\n";

     16: #include <slepcpep.h>

     18: int main(int argc,char **argv)
     19: {
     20:   Mat             M,C,K,A[3];      /* problem matrices */
     21:   PEP             pep;             /* polynomial eigenproblem solver context */
     22:   PetscInt        N,n=10,m,Istart,Iend,II,i,j,midx;
     23:   PetscReal       restart,fix;
     24:   PetscBool       flag,reuse;
     25:   PEPJDProjection proj;
     26:   PetscErrorCode  ierr;

     28:   SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;

     30:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
     31:   PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag);
     32:   if (!flag) m=n;
     33:   N = n*m;
     34:   PetscPrintf(PETSC_COMM_WORLD,"\nQuadratic Eigenproblem, N=%D (%Dx%D grid)\n\n",N,n,m);

     36:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     37:      Compute the matrices that define the eigensystem, (k^2*M+k*C+K)x=0
     38:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     40:   /* K is the 2-D Laplacian */
     41:   MatCreate(PETSC_COMM_WORLD,&K);
     42:   MatSetSizes(K,PETSC_DECIDE,PETSC_DECIDE,N,N);
     43:   MatSetFromOptions(K);
     44:   MatSetUp(K);
     45:   MatGetOwnershipRange(K,&Istart,&Iend);
     46:   for (II=Istart;II<Iend;II++) {
     47:     i = II/n; j = II-i*n;
     48:     if (i>0) { MatSetValue(K,II,II-n,-1.0,INSERT_VALUES); }
     49:     if (i<m-1) { MatSetValue(K,II,II+n,-1.0,INSERT_VALUES); }
     50:     if (j>0) { MatSetValue(K,II,II-1,-1.0,INSERT_VALUES); }
     51:     if (j<n-1) { MatSetValue(K,II,II+1,-1.0,INSERT_VALUES); }
     52:     MatSetValue(K,II,II,4.0,INSERT_VALUES);
     53:   }
     54:   MatAssemblyBegin(K,MAT_FINAL_ASSEMBLY);
     55:   MatAssemblyEnd(K,MAT_FINAL_ASSEMBLY);

     57:   /* C is the 1-D Laplacian on horizontal lines */
     58:   MatCreate(PETSC_COMM_WORLD,&C);
     59:   MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,N,N);
     60:   MatSetFromOptions(C);
     61:   MatSetUp(C);
     62:   MatGetOwnershipRange(C,&Istart,&Iend);
     63:   for (II=Istart;II<Iend;II++) {
     64:     i = II/n; j = II-i*n;
     65:     if (j>0) { MatSetValue(C,II,II-1,-1.0,INSERT_VALUES); }
     66:     if (j<n-1) { MatSetValue(C,II,II+1,-1.0,INSERT_VALUES); }
     67:     MatSetValue(C,II,II,2.0,INSERT_VALUES);
     68:   }
     69:   MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
     70:   MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);

     72:   /* M is a diagonal matrix */
     73:   MatCreate(PETSC_COMM_WORLD,&M);
     74:   MatSetSizes(M,PETSC_DECIDE,PETSC_DECIDE,N,N);
     75:   MatSetFromOptions(M);
     76:   MatSetUp(M);
     77:   MatGetOwnershipRange(M,&Istart,&Iend);
     78:   for (II=Istart;II<Iend;II++) {
     79:     MatSetValue(M,II,II,(PetscReal)(II+1),INSERT_VALUES);
     80:   }
     81:   MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);
     82:   MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);

     84:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     85:                 Create the eigensolver and set various options
     86:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     88:   PEPCreate(PETSC_COMM_WORLD,&pep);
     89:   A[0] = K; A[1] = C; A[2] = M;
     90:   PEPSetOperators(pep,3,A);
     91:   PEPSetType(pep,PEPJD);

     93:   /*
     94:      Test interface functions of STOAR solver
     95:   */
     96:   PEPJDGetRestart(pep,&restart);
     97:   PetscPrintf(PETSC_COMM_WORLD," Restart parameter before changing = %g",(double)restart);
     98:   PEPJDSetRestart(pep,0.3);
     99:   PEPJDGetRestart(pep,&restart);
    100:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %g\n",(double)restart);

    102:   PEPJDGetFix(pep,&fix);
    103:   PetscPrintf(PETSC_COMM_WORLD," Fix parameter before changing = %g",(double)fix);
    104:   PEPJDSetFix(pep,0.001);
    105:   PEPJDGetFix(pep,&fix);
    106:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %g\n",(double)fix);

    108:   PEPJDGetReusePreconditioner(pep,&reuse);
    109:   PetscPrintf(PETSC_COMM_WORLD," Reuse preconditioner flag before changing = %d",(int)reuse);
    110:   PEPJDSetReusePreconditioner(pep,PETSC_TRUE);
    111:   PEPJDGetReusePreconditioner(pep,&reuse);
    112:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %d\n",(int)reuse);

    114:   PEPJDGetProjection(pep,&proj);
    115:   PetscPrintf(PETSC_COMM_WORLD," Projection type before changing = %d",(int)proj);
    116:   PEPJDSetProjection(pep,PEP_JD_PROJECTION_ORTHOGONAL);
    117:   PEPJDGetProjection(pep,&proj);
    118:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %d\n",(int)proj);

    120:   PEPJDGetMinimalityIndex(pep,&midx);
    121:   PetscPrintf(PETSC_COMM_WORLD," Minimality index before changing = %D",midx);
    122:   PEPJDSetMinimalityIndex(pep,2);
    123:   PEPJDGetMinimalityIndex(pep,&midx);
    124:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %D\n",midx);

    126:   PEPSetFromOptions(pep);

    128:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    129:                       Solve the eigensystem
    130:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    132:   PEPSolve(pep);
    133:   PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL);
    134:   PEPDestroy(&pep);
    135:   MatDestroy(&M);
    136:   MatDestroy(&C);
    137:   MatDestroy(&K);
    138:   SlepcFinalize();
    139:   return ierr;
    140: }

    142: /*TEST

    144:    test:
    145:       args: -n 12 -pep_nev 2 -pep_ncv 21 -pep_conv_abs

    147: TEST*/