Date: 2026-03-31T13:23:01+00:00

Actual source code: test1.c

      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 the solution of a PEP without calling PEPSetFromOptions (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"
     15:   "  -type <pep_type> = pep type to test.\n"
     16:   "  -epstype <eps_type> = eps type to test (for linear).\n\n";

     18: #include <slepcpep.h>

     20: int main(int argc,char **argv)
     21: {
     22:   Mat            M,C,K,A[3];      /* problem matrices */
     23:   PEP            pep;             /* polynomial eigenproblem solver context */
     24:   PetscInt       N,n=10,m,Istart,Iend,II,nev,i,j;
     25:   PetscReal      keep;
     26:   PetscBool      flag,isgd2,epsgiven,lock;
     27:   char           peptype[30] = "linear",epstype[30] = "";
     28:   EPS            eps;
     29:   ST             st;
     30:   KSP            ksp;
     31:   PC             pc;

     33:   PetscFunctionBeginUser;
     34:   PetscCall(SlepcInitialize(&argc,&argv,NULL,help));

     36:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
     37:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag));
     38:   if (!flag) m=n;
     39:   N = n*m;
     40:   PetscCall(PetscOptionsGetString(NULL,NULL,"-type",peptype,sizeof(peptype),NULL));
     41:   PetscCall(PetscOptionsGetString(NULL,NULL,"-epstype",epstype,sizeof(epstype),&epsgiven));
     42:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nQuadratic Eigenproblem, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m));

     44:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     45:      Compute the matrices that define the eigensystem, (k^2*M+k*C+K)x=0
     46:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

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

     78:   /* M is a diagonal matrix */
     79:   PetscCall(MatCreate(PETSC_COMM_WORLD,&M));
     80:   PetscCall(MatSetSizes(M,PETSC_DECIDE,PETSC_DECIDE,N,N));
     81:   PetscCall(MatSetFromOptions(M));
     82:   PetscCall(MatGetOwnershipRange(M,&Istart,&Iend));
     83:   for (II=Istart;II<Iend;II++) PetscCall(MatSetValue(M,II,II,(PetscReal)(II+1),INSERT_VALUES));
     84:   PetscCall(MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY));
     85:   PetscCall(MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY));

     87:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     88:                 Create the eigensolver and set various options
     89:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     91:   PetscCall(PEPCreate(PETSC_COMM_WORLD,&pep));
     92:   A[0] = K; A[1] = C; A[2] = M;
     93:   PetscCall(PEPSetOperators(pep,3,A));
     94:   PetscCall(PEPSetProblemType(pep,PEP_GENERAL));
     95:   PetscCall(PEPSetDimensions(pep,4,20,PETSC_DETERMINE));
     96:   PetscCall(PEPSetTolerances(pep,PETSC_SMALL,PETSC_CURRENT));

     98:   /*
     99:      Set solver type at runtime
    100:   */
    101:   PetscCall(PEPSetType(pep,peptype));
    102:   if (epsgiven) {
    103:     PetscCall(PetscObjectTypeCompare((PetscObject)pep,PEPLINEAR,&flag));
    104:     if (flag) {
    105:       PetscCall(PEPLinearGetEPS(pep,&eps));
    106:       PetscCall(PetscStrcmp(epstype,"gd2",&isgd2));
    107:       if (isgd2) {
    108:         PetscCall(EPSSetType(eps,EPSGD));
    109:         PetscCall(EPSGDSetDoubleExpansion(eps,PETSC_TRUE));
    110:       } else PetscCall(EPSSetType(eps,epstype));
    111:       PetscCall(EPSGetST(eps,&st));
    112:       PetscCall(STGetKSP(st,&ksp));
    113:       PetscCall(KSPGetPC(ksp,&pc));
    114:       PetscCall(PCSetType(pc,PCJACOBI));
    115:       PetscCall(PetscObjectTypeCompare((PetscObject)eps,EPSGD,&flag));
    116:     }
    117:     PetscCall(PEPLinearSetExplicitMatrix(pep,PETSC_TRUE));
    118:   }
    119:   PetscCall(PetscObjectTypeCompare((PetscObject)pep,PEPQARNOLDI,&flag));
    120:   if (flag) {
    121:     PetscCall(STCreate(PETSC_COMM_WORLD,&st));
    122:     PetscCall(STSetTransform(st,PETSC_TRUE));
    123:     PetscCall(PEPSetST(pep,st));
    124:     PetscCall(STDestroy(&st));
    125:     PetscCall(PEPQArnoldiGetRestart(pep,&keep));
    126:     PetscCall(PEPQArnoldiGetLocking(pep,&lock));
    127:     if (!lock && keep<0.6) PetscCall(PEPQArnoldiSetRestart(pep,0.6));
    128:   }
    129:   PetscCall(PetscObjectTypeCompare((PetscObject)pep,PEPTOAR,&flag));
    130:   if (flag) {
    131:     PetscCall(PEPTOARGetRestart(pep,&keep));
    132:     PetscCall(PEPTOARGetLocking(pep,&lock));
    133:     if (!lock && keep<0.6) PetscCall(PEPTOARSetRestart(pep,0.6));
    134:   }

    136:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    137:                       Solve the eigensystem
    138:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    140:   PetscCall(PEPSolve(pep));
    141:   PetscCall(PEPGetDimensions(pep,&nev,NULL,NULL));
    142:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %" PetscInt_FMT "\n",nev));

    144:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    145:                     Display solution and clean up
    146:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    148:   PetscCall(PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL));
    149:   PetscCall(PEPDestroy(&pep));
    150:   PetscCall(MatDestroy(&M));
    151:   PetscCall(MatDestroy(&C));
    152:   PetscCall(MatDestroy(&K));
    153:   PetscCall(SlepcFinalize());
    154:   return 0;
    155: }

    157: /*TEST

    159:    testset:
    160:       args: -m 11
    161:       output_file: output/test1_1.out
    162:       filter: sed -e "s/1.16403/1.16404/g" | sed -e "s/1.65362i/1.65363i/g" | sed -e "s/-1.16404-1.65363i, -1.16404+1.65363i/-1.16404+1.65363i, -1.16404-1.65363i/" | sed -e "s/-0.51784-1.31039i, -0.51784+1.31039i/-0.51784+1.31039i, -0.51784-1.31039i/"
    163:       requires: !single
    164:       test:
    165:          suffix: 1
    166:          args: -type {{toar qarnoldi linear}}
    167:       test:
    168:          suffix: 1_linear_gd
    169:          args: -type linear -epstype gd
    170:          requires: !__float128

    172: TEST*/