Date: 2024-12-02T08:57:40+00:00

Actual source code: test8.c
slepc-3.22.2 2024-12-02
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-, 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;

     27:   PetscFunctionBeginUser;
     28:   PetscCall(SlepcInitialize(&argc,&argv,NULL,help));

     30:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
     31:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag));
     32:   if (!flag) m=n;
     33:   N = n*m;
     34:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nQuadratic Eigenproblem, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " 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:   PetscCall(MatCreate(PETSC_COMM_WORLD,&K));
     42:   PetscCall(MatSetSizes(K,PETSC_DECIDE,PETSC_DECIDE,N,N));
     43:   PetscCall(MatSetFromOptions(K));
     44:   PetscCall(MatGetOwnershipRange(K,&Istart,&Iend));
     45:   for (II=Istart;II<Iend;II++) {
     46:     i = II/n; j = II-i*n;
     47:     if (i>0) PetscCall(MatSetValue(K,II,II-n,-1.0,INSERT_VALUES));
     48:     if (i<m-1) PetscCall(MatSetValue(K,II,II+n,-1.0,INSERT_VALUES));
     49:     if (j>0) PetscCall(MatSetValue(K,II,II-1,-1.0,INSERT_VALUES));
     50:     if (j<n-1) PetscCall(MatSetValue(K,II,II+1,-1.0,INSERT_VALUES));
     51:     PetscCall(MatSetValue(K,II,II,4.0,INSERT_VALUES));
     52:   }
     53:   PetscCall(MatAssemblyBegin(K,MAT_FINAL_ASSEMBLY));
     54:   PetscCall(MatAssemblyEnd(K,MAT_FINAL_ASSEMBLY));

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

     70:   /* M is a diagonal matrix */
     71:   PetscCall(MatCreate(PETSC_COMM_WORLD,&M));
     72:   PetscCall(MatSetSizes(M,PETSC_DECIDE,PETSC_DECIDE,N,N));
     73:   PetscCall(MatSetFromOptions(M));
     74:   PetscCall(MatGetOwnershipRange(M,&Istart,&Iend));
     75:   for (II=Istart;II<Iend;II++) PetscCall(MatSetValue(M,II,II,(PetscReal)(II+1),INSERT_VALUES));
     76:   PetscCall(MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY));
     77:   PetscCall(MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY));

     79:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     80:                 Create the eigensolver and set various options
     81:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     83:   PetscCall(PEPCreate(PETSC_COMM_WORLD,&pep));
     84:   A[0] = K; A[1] = C; A[2] = M;
     85:   PetscCall(PEPSetOperators(pep,3,A));
     86:   PetscCall(PEPSetType(pep,PEPJD));

     88:   /*
     89:      Test interface functions of JD solver
     90:   */
     91:   PetscCall(PEPJDGetRestart(pep,&restart));
     92:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Restart parameter before changing = %g",(double)restart));
     93:   PetscCall(PEPJDSetRestart(pep,0.3));
     94:   PetscCall(PEPJDGetRestart(pep,&restart));
     95:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," ... changed to %g\n",(double)restart));

     97:   PetscCall(PEPJDGetFix(pep,&fix));
     98:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Fix parameter before changing = %g",(double)fix));
     99:   PetscCall(PEPJDSetFix(pep,0.001));
    100:   PetscCall(PEPJDGetFix(pep,&fix));
    101:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," ... changed to %g\n",(double)fix));

    103:   PetscCall(PEPJDGetReusePreconditioner(pep,&reuse));
    104:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Reuse preconditioner flag before changing = %d",(int)reuse));
    105:   PetscCall(PEPJDSetReusePreconditioner(pep,PETSC_TRUE));
    106:   PetscCall(PEPJDGetReusePreconditioner(pep,&reuse));
    107:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," ... changed to %d\n",(int)reuse));

    109:   PetscCall(PEPJDGetProjection(pep,&proj));
    110:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Projection type before changing = %d",(int)proj));
    111:   PetscCall(PEPJDSetProjection(pep,PEP_JD_PROJECTION_ORTHOGONAL));
    112:   PetscCall(PEPJDGetProjection(pep,&proj));
    113:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," ... changed to %d\n",(int)proj));

    115:   PetscCall(PEPJDGetMinimalityIndex(pep,&midx));
    116:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Minimality index before changing = %" PetscInt_FMT,midx));
    117:   PetscCall(PEPJDSetMinimalityIndex(pep,2));
    118:   PetscCall(PEPJDGetMinimalityIndex(pep,&midx));
    119:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," ... changed to %" PetscInt_FMT "\n",midx));

    121:   PetscCall(PEPSetFromOptions(pep));

    123:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    124:                       Solve the eigensystem
    125:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    127:   PetscCall(PEPSolve(pep));
    128:   PetscCall(PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL));
    129:   PetscCall(PEPDestroy(&pep));
    130:   PetscCall(MatDestroy(&M));
    131:   PetscCall(MatDestroy(&C));
    132:   PetscCall(MatDestroy(&K));
    133:   PetscCall(SlepcFinalize());
    134:   return 0;
    135: }

    137: /*TEST

    139:    test:
    140:       args: -n 12 -pep_nev 2 -pep_ncv 21 -pep_conv_abs

    142: TEST*/