Date: 2022-08-09T09:05:39+00:00

Actual source code: test34.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 to external package PRIMME.\n\n"
     12:   "This is based on ex3.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 <slepceps.h>

     18: int main(int argc,char **argv)
     19: {
     20:   Mat             A;           /* matrix */
     21:   EPS             eps;         /* eigenproblem solver context */
     22:   ST              st;          /* spectral transformation context */
     23:   KSP             ksp;
     24:   PC              pc;
     25:   PetscInt        N,n=35,m,Istart,Iend,II,i,j,bs;
     26:   PetscBool       flag;
     27:   EPSPRIMMEMethod meth;

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

     31:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
     32:   PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag);
     33:   if (!flag) m=n;
     34:   N = n*m;
     35:   PetscPrintf(PETSC_COMM_WORLD,"\nStandard eigenproblem with PRIMME, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m);

     37:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     38:          Compute the matrices that define the eigensystem, Ax=kBx
     39:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     41:   MatCreate(PETSC_COMM_WORLD,&A);
     42:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N);
     43:   MatSetFromOptions(A);
     44:   MatSetUp(A);

     46:   MatGetOwnershipRange(A,&Istart,&Iend);
     47:   for (II=Istart;II<Iend;II++) {
     48:     i = II/n; j = II-i*n;
     49:     if (i>0) MatSetValue(A,II,II-n,-1.0,INSERT_VALUES);
     50:     if (i<m-1) MatSetValue(A,II,II+n,-1.0,INSERT_VALUES);
     51:     if (j>0) MatSetValue(A,II,II-1,-1.0,INSERT_VALUES);
     52:     if (j<n-1) MatSetValue(A,II,II+1,-1.0,INSERT_VALUES);
     53:     MatSetValue(A,II,II,4.0,INSERT_VALUES);
     54:   }

     56:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
     57:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

     59:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     60:                 Create the eigensolver and set various options
     61:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     63:   EPSCreate(PETSC_COMM_WORLD,&eps);
     64:   EPSSetOperators(eps,A,NULL);
     65:   EPSSetProblemType(eps,EPS_HEP);
     66:   EPSSetType(eps,EPSPRIMME);

     68:   /*
     69:      Set several options
     70:   */
     71:   EPSSetWhichEigenpairs(eps,EPS_SMALLEST_REAL);
     72:   EPSGetST(eps,&st);
     73:   STSetType(st,STPRECOND);
     74:   STGetKSP(st,&ksp);
     75:   KSPGetPC(ksp,&pc);
     76:   KSPSetType(ksp,KSPPREONLY);
     77:   PCSetType(pc,PCICC);

     79:   EPSPRIMMESetBlockSize(eps,4);
     80:   EPSPRIMMESetMethod(eps,EPS_PRIMME_GD_OLSEN_PLUSK);
     81:   EPSSetFromOptions(eps);

     83:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     84:                  Compute eigenvalues and display info
     85:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     87:   EPSSolve(eps);
     88:   EPSPRIMMEGetBlockSize(eps,&bs);
     89:   EPSPRIMMEGetMethod(eps,&meth);
     90:   PetscPrintf(PETSC_COMM_WORLD," PRIMME: using block size %" PetscInt_FMT ", method %s\n",bs,EPSPRIMMEMethods[meth]);

     92:   EPSErrorView(eps,EPS_ERROR_ABSOLUTE,NULL);

     94:   EPSDestroy(&eps);
     95:   MatDestroy(&A);
     96:   SlepcFinalize();
     97:   return 0;
     98: }

    100: /*TEST

    102:    build:
    103:       requires: primme

    105:    testset:
    106:       args: -eps_nev 4
    107:       requires: primme
    108:       output_file: output/test34_1.out
    109:       test:
    110:          suffix: 1
    111:       test:
    112:          suffix: 2
    113:          args: -st_pc_type bjacobi -eps_target 0.01 -eps_target_real -eps_refined
    114:          nsize: 2
    115:       test:
    116:          suffix: 3
    117:          args: -eps_smallest_magnitude -eps_harmonic

    119: TEST*/