Actual source code: test36.c

slepc-3.16.0 2021-09-30
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2021, 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);if (ierr) return ierr;
 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=%D (%Dx%D 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 ierr;
 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*/