Date: 2022-11-02T11:46:58+00:00

Actual source code: test36.c
slepc-3.18.1 2022-11-02
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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[] = "Tests a HEP problem with Hermitian matrix.\n\n";

     13: #include <slepceps.h>

     15: int main(int argc,char **argv)
     16: {
     17:   Mat            A;          /* matrix */
     18:   EPS            eps;        /* eigenproblem solver context */
     19:   PetscInt       N,n=20,m,Istart,Iend,II,i,j;
     20:   PetscBool      flag;

     23:   SlepcInitialize(&argc,&argv,(char*)0,help);
     24:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
     25:   PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag);
     26:   if (!flag) m=n;
     27:   N = n*m;
     28:   PetscPrintf(PETSC_COMM_WORLD,"\nHermitian Eigenproblem, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m);
     29: #if !defined(PETSC_USE_COMPLEX)
     30:   SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"This example requires complex scalars!");
     31: #endif

     33:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     34:      Compute the matrix that defines the eigensystem, Ax=kx
     35:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     37:   MatCreate(PETSC_COMM_WORLD,&A);
     38:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N);
     39:   MatSetFromOptions(A);
     40:   MatSetUp(A);

     42:   MatGetOwnershipRange(A,&Istart,&Iend);
     43:   for (II=Istart;II<Iend;II++) {
     44:     i = II/n; j = II-i*n;
     45:     if (i>0) MatSetValue(A,II,II-n,-1.0-0.1*PETSC_i,INSERT_VALUES);
     46:     if (i<m-1) MatSetValue(A,II,II+n,-1.0+0.1*PETSC_i,INSERT_VALUES);
     47:     if (j>0) MatSetValue(A,II,II-1,-1.0-0.1*PETSC_i,INSERT_VALUES);
     48:     if (j<n-1) MatSetValue(A,II,II+1,-1.0+0.1*PETSC_i,INSERT_VALUES);
     49:     MatSetValue(A,II,II,4.0,INSERT_VALUES);
     50:   }
     51:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
     52:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

     54:   MatSetOption(A,MAT_HERMITIAN,PETSC_TRUE);

     56:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     57:                 Create the eigensolver and solve the problem
     58:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     60:   EPSCreate(PETSC_COMM_WORLD,&eps);
     61:   EPSSetOperators(eps,A,NULL);
     62:   EPSSetProblemType(eps,EPS_HEP);
     63:   EPSSetFromOptions(eps);
     64:   EPSSolve(eps);
     65:   EPSErrorView(eps,EPS_ERROR_BACKWARD,NULL);

     67:   EPSDestroy(&eps);
     68:   MatDestroy(&A);
     69:   SlepcFinalize();
     70:   return 0;
     71: }

     73: /*TEST

     75:    build:
     76:       requires: complex

     78:    testset:
     79:       args: -m 18 -n 19 -eps_nev 4 -eps_max_it 1000
     80:       requires: !single complex
     81:       output_file: output/test36_1.out
     82:       test:
     83:          suffix: 1
     84:          args: -eps_type {{krylovschur subspace arnoldi gd jd lapack}}
     85:       test:
     86:          suffix: 1_elemental
     87:          args: -eps_type elemental
     88:          requires: elemental

     90:    test:
     91:       suffix: 2
     92:       args: -eps_nev 4 -eps_smallest_real -eps_type {{lobpcg rqcg lapack}}
     93:       requires: !single complex

     95: TEST*/