Actual source code: test10.c

slepc-3.14.0 2020-09-30
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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[] = "Tests a user-defined convergence test in PEP (based on ex16.c).\n\n"
 12:   "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: /*
 19:   MyConvergedRel - Convergence test relative to the norm of M (given in ctx).
 20: */
 21: PetscErrorCode MyConvergedRel(PEP pep,PetscScalar eigr,PetscScalar eigi,PetscReal res,PetscReal *errest,void *ctx)
 22: {
 23:   PetscReal norm = *(PetscReal*)ctx;

 26:   *errest = res/norm;
 27:   return(0);
 28: }

 30: int main(int argc,char **argv)
 31: {
 32:   Mat            M,C,K,A[3];      /* problem matrices */
 33:   PEP            pep;             /* polynomial eigenproblem solver context */
 34:   PetscInt       N,n=10,m,Istart,Iend,II,nev,i,j;
 35:   PetscBool      flag;
 36:   PetscReal      norm;

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

 41:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 42:   PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag);
 43:   if (!flag) m=n;
 44:   N = n*m;
 45:   PetscPrintf(PETSC_COMM_WORLD,"\nQuadratic Eigenproblem, N=%D (%Dx%D grid)\n\n",N,n,m);

 47:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 48:      Compute the matrices that define the eigensystem, (k^2*M+k*C+K)x=0
 49:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 51:   /* K is the 2-D Laplacian */
 52:   MatCreate(PETSC_COMM_WORLD,&K);
 53:   MatSetSizes(K,PETSC_DECIDE,PETSC_DECIDE,N,N);
 54:   MatSetFromOptions(K);
 55:   MatSetUp(K);
 56:   MatGetOwnershipRange(K,&Istart,&Iend);
 57:   for (II=Istart;II<Iend;II++) {
 58:     i = II/n; j = II-i*n;
 59:     if (i>0) { MatSetValue(K,II,II-n,-1.0,INSERT_VALUES); }
 60:     if (i<m-1) { MatSetValue(K,II,II+n,-1.0,INSERT_VALUES); }
 61:     if (j>0) { MatSetValue(K,II,II-1,-1.0,INSERT_VALUES); }
 62:     if (j<n-1) { MatSetValue(K,II,II+1,-1.0,INSERT_VALUES); }
 63:     MatSetValue(K,II,II,4.0,INSERT_VALUES);
 64:   }
 65:   MatAssemblyBegin(K,MAT_FINAL_ASSEMBLY);
 66:   MatAssemblyEnd(K,MAT_FINAL_ASSEMBLY);

 68:   /* C is the 1-D Laplacian on horizontal lines */
 69:   MatCreate(PETSC_COMM_WORLD,&C);
 70:   MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,N,N);
 71:   MatSetFromOptions(C);
 72:   MatSetUp(C);
 73:   MatGetOwnershipRange(C,&Istart,&Iend);
 74:   for (II=Istart;II<Iend;II++) {
 75:     i = II/n; j = II-i*n;
 76:     if (j>0) { MatSetValue(C,II,II-1,-1.0,INSERT_VALUES); }
 77:     if (j<n-1) { MatSetValue(C,II,II+1,-1.0,INSERT_VALUES); }
 78:     MatSetValue(C,II,II,2.0,INSERT_VALUES);
 79:   }
 80:   MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
 81:   MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);

 83:   /* M is a diagonal matrix */
 84:   MatCreate(PETSC_COMM_WORLD,&M);
 85:   MatSetSizes(M,PETSC_DECIDE,PETSC_DECIDE,N,N);
 86:   MatSetFromOptions(M);
 87:   MatSetUp(M);
 88:   MatGetOwnershipRange(M,&Istart,&Iend);
 89:   for (II=Istart;II<Iend;II++) {
 90:     MatSetValue(M,II,II,(PetscReal)(II+1),INSERT_VALUES);
 91:   }
 92:   MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);
 93:   MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);

 95:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 96:                 Create the eigensolver and set various options
 97:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 99:   PEPCreate(PETSC_COMM_WORLD,&pep);
100:   A[0] = K; A[1] = C; A[2] = M;
101:   PEPSetOperators(pep,3,A);
102:   PEPSetProblemType(pep,PEP_HERMITIAN);
103:   PEPSetDimensions(pep,4,20,PETSC_DEFAULT);

105:   /* setup convergence test relative to the norm of M */
106:   MatNorm(M,NORM_1,&norm);
107:   PEPSetConvergenceTestFunction(pep,MyConvergedRel,&norm,NULL);
108:   PEPSetFromOptions(pep);

110:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
111:                       Solve the eigensystem
112:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

114:   PEPSolve(pep);
115:   PEPGetDimensions(pep,&nev,NULL,NULL);
116:   PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %D\n",nev);

118:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
119:                     Display solution and clean up
120:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

122:   PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL);
123:   PEPDestroy(&pep);
124:   MatDestroy(&M);
125:   MatDestroy(&C);
126:   MatDestroy(&K);
127:   SlepcFinalize();
128:   return ierr;
129: }

131: /*TEST

133:    testset:
134:       requires: double
135:       suffix: 1

137: TEST*/