Date: 2021-02-01T14:42:20+00:00

Actual source code: test3.c
slepc-3.14.2 2021-02-01
Report Typos and Errors

      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2020, 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 MFN interface functions.\n\n"
     12:   "The command line options are:\n"
     13:   "  -n <n>, where <n> = number of grid subdivisions in x dimension.\n\n";

     15: #include <slepcmfn.h>

     17: int main(int argc,char **argv)
     18: {
     19:   Mat                  A,B;
     20:   MFN                  mfn;
     21:   FN                   f;
     22:   MFNConvergedReason   reason;
     23:   MFNType              type;
     24:   PetscReal            norm,tol;
     25:   Vec                  v,y;
     26:   PetscInt             N,n=4,Istart,Iend,i,j,II,ncv,its,maxit;
     27:   PetscBool            flg,testprefix=PETSC_FALSE;
     28:   const char           *prefix;
     29:   PetscErrorCode       ierr;
     30:   PetscViewerAndFormat *vf;

     32:   SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
     33:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
     34:   N = n*n;
     35:   PetscPrintf(PETSC_COMM_WORLD,"\nSquare root of Laplacian y=sqrt(A)*e_1, N=%D (%Dx%D grid)\n\n",N,n,n);
     36:   PetscOptionsGetBool(NULL,NULL,"-test_prefix",&testprefix,NULL);

     38:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     39:                  Compute the discrete 2-D Laplacian, A
     40:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

     47:   MatGetOwnershipRange(A,&Istart,&Iend);
     48:   for (II=Istart;II<Iend;II++) {
     49:     i = II/n; j = II-i*n;
     50:     if (i>0) { MatSetValue(A,II,II-n,-1.0,INSERT_VALUES); }
     51:     if (i<n-1) { MatSetValue(A,II,II+n,-1.0,INSERT_VALUES); }
     52:     if (j>0) { MatSetValue(A,II,II-1,-1.0,INSERT_VALUES); }
     53:     if (j<n-1) { MatSetValue(A,II,II+1,-1.0,INSERT_VALUES); }
     54:     MatSetValue(A,II,II,4.0,INSERT_VALUES);
     55:   }

     57:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
     58:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
     59:   MatSetOption(A,MAT_HERMITIAN,PETSC_TRUE);

     61:   MatCreateVecs(A,NULL,&v);
     62:   VecSetValue(v,0,1.0,INSERT_VALUES);
     63:   VecAssemblyBegin(v);
     64:   VecAssemblyEnd(v);
     65:   VecDuplicate(v,&y);

     67:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     68:              Create the solver, set the matrix and the function
     69:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
     70:   MFNCreate(PETSC_COMM_WORLD,&mfn);
     71:   MFNSetOperator(mfn,A);
     72:   MFNGetFN(mfn,&f);
     73:   FNSetType(f,FNSQRT);

     75:   MFNSetType(mfn,MFNKRYLOV);
     76:   MFNGetType(mfn,&type);
     77:   PetscPrintf(PETSC_COMM_WORLD," Type set to %s\n",type);

     79:   /* test prefix usage */
     80:   if (testprefix) {
     81:     MFNSetOptionsPrefix(mfn,"check_");
     82:     MFNAppendOptionsPrefix(mfn,"myprefix_");
     83:     MFNGetOptionsPrefix(mfn,&prefix);
     84:     PetscPrintf(PETSC_COMM_WORLD," MFN prefix is currently: %s\n",prefix);
     85:   }

     87:   /* test some interface functions */
     88:   MFNGetOperator(mfn,&B);
     89:   MatView(B,PETSC_VIEWER_STDOUT_WORLD);
     90:   MFNSetTolerances(mfn,1e-4,500);
     91:   MFNSetDimensions(mfn,6);
     92:   MFNSetErrorIfNotConverged(mfn,PETSC_TRUE);
     93:   /* test monitors */
     94:   PetscViewerAndFormatCreate(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_DEFAULT,&vf);
     95:   MFNMonitorSet(mfn,(PetscErrorCode (*)(MFN,PetscInt,PetscReal,void*))MFNMonitorDefault,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
     96:   /* MFNMonitorCancel(mfn); */
     97:   MFNSetFromOptions(mfn);

     99:   /* query properties and print them */
    100:   MFNGetTolerances(mfn,&tol,&maxit);
    101:   PetscPrintf(PETSC_COMM_WORLD," Tolerance: %g, max iterations: %D\n",(double)tol,maxit);
    102:   MFNGetDimensions(mfn,&ncv);
    103:   PetscPrintf(PETSC_COMM_WORLD," Subspace dimension: %D\n",ncv);
    104:   MFNGetErrorIfNotConverged(mfn,&flg);
    105:   if (flg) { PetscPrintf(PETSC_COMM_WORLD," Erroring out if convergence fails\n"); }

    107:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    108:                            Solve  y=sqrt(A)*v
    109:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    111:   MFNSolve(mfn,v,y);
    112:   MFNGetConvergedReason(mfn,&reason);
    113:   MFNGetIterationNumber(mfn,&its);
    114:   PetscPrintf(PETSC_COMM_WORLD," Finished - converged reason = %d\n",(int)reason);
    115:   /* PetscPrintf(PETSC_COMM_WORLD," its = %D\n",its); */
    116:   VecNorm(y,NORM_2,&norm);
    117:   PetscPrintf(PETSC_COMM_WORLD," sqrt(A)*v has norm %g\n",(double)norm);

    119:   /*
    120:      Free work space
    121:   */
    122:   MFNDestroy(&mfn);
    123:   MatDestroy(&A);
    124:   VecDestroy(&v);
    125:   VecDestroy(&y);
    126:   SlepcFinalize();
    127:   return ierr;
    128: }

    130: /*TEST

    132:    test:
    133:       suffix: 1
    134:       args: -mfn_monitor_cancel -mfn_converged_reason -mfn_view -log_exclude mfn,bv,fn

    136:    test:
    137:       suffix: 2
    138:       args: -test_prefix -check_myprefix_mfn_monitor
    139:       filter: sed -e "s/estimate [0-9]\.[0-9]*e[+-]\([0-9]*\)/estimate (removed)/g" | sed -e "s/4.0[0-9]*e-10/4.03e-10/"

    141: TEST*/