Date: 2022-08-09T09:05:50+00:00

Actual source code: test7.c
slepc-3.17.2 2022-08-09
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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;

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

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

     34:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     35:      Compute the matrices that define the eigensystem, (k^2*M+k*C+K)x=0
     36:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

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

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

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

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

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

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

     80:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     81:                 Create the eigensolver and solve the problem
     82:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

     90:   /*
     91:      Set interval and other settings for spectrum slicing
     92:   */
     93:   int0 = -11.3;
     94:   int1 = -9.5;
     95:   PEPSetInterval(pep,int0,int1);
     96:   PEPSetWhichEigenpairs(pep,PEP_ALL);
     97:   PEPGetST(pep,&st);
     98:   STSetType(st,STSINVERT);
     99:   STGetKSP(st,&ksp);
    100:   KSPSetType(ksp,KSPPREONLY);
    101:   KSPGetPC(ksp,&pc);
    102:   PCSetType(pc,PCCHOLESKY);

    104:   /*
    105:      Test interface functions of STOAR solver
    106:   */
    107:   PEPSTOARGetDetectZeros(pep,&detect);
    108:   PetscPrintf(PETSC_COMM_WORLD," Detect zeros before changing = %d",(int)detect);
    109:   PEPSTOARSetDetectZeros(pep,PETSC_TRUE);
    110:   PEPSTOARGetDetectZeros(pep,&detect);
    111:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %d\n",(int)detect);

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

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

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

    131:   PEPSetFromOptions(pep);

    133:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    134:              Compute all eigenvalues in interval and display info
    135:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

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

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

    157:   PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL);

    159:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    160:                     Clean up
    161:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    162:   PEPDestroy(&pep);
    163:   MatDestroy(&M);
    164:   MatDestroy(&C);
    165:   MatDestroy(&K);
    166:   SlepcFinalize();
    167:   return 0;
    168: }

    170: /*TEST

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

    176: TEST*/