Actual source code: test8.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[] = "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*/