Date: 2022-10-01T06:40:27+00:00

Actual source code: test7.c
slepc-3.18.0 2022-10-01
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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[] = "Test interface functions of spectrum-slicing STOAR.\n\n"
     12:   "This is based on ex38.c. The command line options are:\n"
     13:   "  -n <n> ... dimension of the matrices.\n\n";

     15: #include <slepcpep.h>

     17: int main(int argc,char **argv)
     18: {
     19:   Mat            M,C,K,A[3]; /* problem matrices */
     20:   PEP            pep;        /* polynomial eigenproblem solver context */
     21:   ST             st;         /* spectral transformation context */
     22:   KSP            ksp;
     23:   PC             pc;
     24:   PetscBool      showinertia=PETSC_TRUE,lock,detect,checket;
     25:   PetscInt       n=100,Istart,Iend,i,*inertias,ns,nev,ncv,mpd;
     26:   PetscReal      mu=1.0,tau=10.0,kappa=5.0,int0,int1,*shifts;

     29:   SlepcInitialize(&argc,&argv,(char*)0,help);

     31:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
     32:   PetscOptionsGetBool(NULL,NULL,"-showinertia",&showinertia,NULL);
     33:   PetscPrintf(PETSC_COMM_WORLD,"\nSpectrum slicing on PEP, n=%" PetscInt_FMT "\n\n",n);

     35:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     36:      Compute the matrices that define the eigensystem, (k^2*M+k*C+K)x=0
     37:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     39:   /* K is a tridiagonal */
     40:   MatCreate(PETSC_COMM_WORLD,&K);
     41:   MatSetSizes(K,PETSC_DECIDE,PETSC_DECIDE,n,n);
     42:   MatSetFromOptions(K);
     43:   MatSetUp(K);

     45:   MatGetOwnershipRange(K,&Istart,&Iend);
     46:   for (i=Istart;i<Iend;i++) {
     47:     if (i>0) MatSetValue(K,i,i-1,-kappa,INSERT_VALUES);
     48:     MatSetValue(K,i,i,kappa*3.0,INSERT_VALUES);
     49:     if (i<n-1) MatSetValue(K,i,i+1,-kappa,INSERT_VALUES);
     50:   }

     52:   MatAssemblyBegin(K,MAT_FINAL_ASSEMBLY);
     53:   MatAssemblyEnd(K,MAT_FINAL_ASSEMBLY);

     55:   /* C is a tridiagonal */
     56:   MatCreate(PETSC_COMM_WORLD,&C);
     57:   MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,n,n);
     58:   MatSetFromOptions(C);
     59:   MatSetUp(C);

     61:   MatGetOwnershipRange(C,&Istart,&Iend);
     62:   for (i=Istart;i<Iend;i++) {
     63:     if (i>0) MatSetValue(C,i,i-1,-tau,INSERT_VALUES);
     64:     MatSetValue(C,i,i,tau*3.0,INSERT_VALUES);
     65:     if (i<n-1) MatSetValue(C,i,i+1,-tau,INSERT_VALUES);
     66:   }

     68:   MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
     69:   MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);

     71:   /* M is a diagonal matrix */
     72:   MatCreate(PETSC_COMM_WORLD,&M);
     73:   MatSetSizes(M,PETSC_DECIDE,PETSC_DECIDE,n,n);
     74:   MatSetFromOptions(M);
     75:   MatSetUp(M);
     76:   MatGetOwnershipRange(M,&Istart,&Iend);
     77:   for (i=Istart;i<Iend;i++) MatSetValue(M,i,i,mu,INSERT_VALUES);
     78:   MatAssemblyBegin(M,MAT_FINAL_ASSEMBLY);
     79:   MatAssemblyEnd(M,MAT_FINAL_ASSEMBLY);

     81:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     82:                 Create the eigensolver and solve the problem
     83:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     85:   PEPCreate(PETSC_COMM_WORLD,&pep);
     86:   A[0] = K; A[1] = C; A[2] = M;
     87:   PEPSetOperators(pep,3,A);
     88:   PEPSetProblemType(pep,PEP_HYPERBOLIC);
     89:   PEPSetType(pep,PEPSTOAR);

     91:   /*
     92:      Set interval and other settings for spectrum slicing
     93:   */
     94:   int0 = -11.3;
     95:   int1 = -9.5;
     96:   PEPSetInterval(pep,int0,int1);
     97:   PEPSetWhichEigenpairs(pep,PEP_ALL);
     98:   PEPGetST(pep,&st);
     99:   STSetType(st,STSINVERT);
    100:   STGetKSP(st,&ksp);
    101:   KSPSetType(ksp,KSPPREONLY);
    102:   KSPGetPC(ksp,&pc);
    103:   PCSetType(pc,PCCHOLESKY);

    105:   /*
    106:      Test interface functions of STOAR solver
    107:   */
    108:   PEPSTOARGetDetectZeros(pep,&detect);
    109:   PetscPrintf(PETSC_COMM_WORLD," Detect zeros before changing = %d",(int)detect);
    110:   PEPSTOARSetDetectZeros(pep,PETSC_TRUE);
    111:   PEPSTOARGetDetectZeros(pep,&detect);
    112:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %d\n",(int)detect);

    114:   PEPSTOARGetLocking(pep,&lock);
    115:   PetscPrintf(PETSC_COMM_WORLD," Locking flag before changing = %d",(int)lock);
    116:   PEPSTOARSetLocking(pep,PETSC_TRUE);
    117:   PEPSTOARGetLocking(pep,&lock);
    118:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %d\n",(int)lock);

    120:   PEPSTOARGetCheckEigenvalueType(pep,&checket);
    121:   PetscPrintf(PETSC_COMM_WORLD," Check eigenvalue type flag before changing = %d",(int)checket);
    122:   PEPSTOARSetCheckEigenvalueType(pep,PETSC_FALSE);
    123:   PEPSTOARGetCheckEigenvalueType(pep,&checket);
    124:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %d\n",(int)checket);

    126:   PEPSTOARGetDimensions(pep,&nev,&ncv,&mpd);
    127:   PetscPrintf(PETSC_COMM_WORLD," Sub-solve dimensions before changing = [%" PetscInt_FMT ",%" PetscInt_FMT ",%" PetscInt_FMT "]",nev,ncv,mpd);
    128:   PEPSTOARSetDimensions(pep,30,60,60);
    129:   PEPSTOARGetDimensions(pep,&nev,&ncv,&mpd);
    130:   PetscPrintf(PETSC_COMM_WORLD," ... changed to [%" PetscInt_FMT ",%" PetscInt_FMT ",%" PetscInt_FMT "]\n",nev,ncv,mpd);

    132:   PEPSetFromOptions(pep);

    134:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    135:              Compute all eigenvalues in interval and display info
    136:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    138:   PEPSetUp(pep);
    139:   PEPSTOARGetInertias(pep,&ns,&shifts,&inertias);
    140:   PetscPrintf(PETSC_COMM_WORLD," Inertias (after setup):\n");
    141:   for (i=0;i<ns;i++) PetscPrintf(PETSC_COMM_WORLD," .. %g (%" PetscInt_FMT ")\n",(double)shifts[i],inertias[i]);
    142:   PetscFree(shifts);
    143:   PetscFree(inertias);

    145:   PEPSolve(pep);
    146:   PEPGetDimensions(pep,&nev,NULL,NULL);
    147:   PEPGetInterval(pep,&int0,&int1);
    148:   PetscPrintf(PETSC_COMM_WORLD," Found %" PetscInt_FMT " eigenvalues in interval [%g,%g]\n",nev,(double)int0,(double)int1);

    150:   if (showinertia) {
    151:     PEPSTOARGetInertias(pep,&ns,&shifts,&inertias);
    152:     PetscPrintf(PETSC_COMM_WORLD," Used %" PetscInt_FMT " shifts (inertia):\n",ns);
    153:     for (i=0;i<ns;i++) PetscPrintf(PETSC_COMM_WORLD," .. %g (%" PetscInt_FMT ")\n",(double)shifts[i],inertias[i]);
    154:     PetscFree(shifts);
    155:     PetscFree(inertias);
    156:   }

    158:   PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL);

    160:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    161:                     Clean up
    162:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    163:   PEPDestroy(&pep);
    164:   MatDestroy(&M);
    165:   MatDestroy(&C);
    166:   MatDestroy(&K);
    167:   SlepcFinalize();
    168:   return 0;
    169: }

    171: /*TEST

    173:    test:
    174:       requires: !single
    175:       args: -showinertia 0

    177: TEST*/