Actual source code: test3.c

slepc-3.20.1 2023-11-27
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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 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:   PetscViewerAndFormat *vf;

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

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

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

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

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

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

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

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

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

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

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

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

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

119:   /*
120:      Free work space
121:   */
122:   PetscCall(MFNDestroy(&mfn));
123:   PetscCall(MatDestroy(&A));
124:   PetscCall(VecDestroy(&v));
125:   PetscCall(VecDestroy(&y));
126:   PetscCall(SlepcFinalize());
127:   return 0;
128: }

130: /*TEST

132:    test:
133:       suffix: 1
134:       args: -mfn_monitor_cancel -mfn_converged_reason -mfn_view -log_exclude mfn,bv,fn -mfn_monitor draw::draw_lg -draw_virtual
135:       requires: x

137:    test:
138:       suffix: 2
139:       args: -test_prefix -check_myprefix_mfn_monitor
140:       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/"

142: TEST*/