src/foam/matrices/blockLduMatrix/BlockLduSolvers/BlockAmgSolver/BlockAmgSolver.C

   1 /*---------------------------------------------------------------------------*\
   2   =========                 |
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   7 -------------------------------------------------------------------------------
   8 License
   9     This file is part of foam-extend.
  10
  11     foam-extend is free software: you can redistribute it and/or modify it
  12     under the terms of the GNU General Public License as published by the
  13     Free Software Foundation, either version 3 of the License, or (at your
  14     option) any later version.
  15
  16     foam-extend is distributed in the hope that it will be useful, but
  17     WITHOUT ANY WARRANTY; without even the implied warranty of
  18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19     General Public License for more details.
  20
  21     You should have received a copy of the GNU General Public License
  22     along with foam-extend.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 Description
  25     Algebraic Multigrid solver with run-time selection of coarsening and cycle
  26
  27 Author
  28     Klas Jareteg, 2013-04-15
  29
  30 \*---------------------------------------------------------------------------*/
  31
  32 #include "BlockAmgSolver.H"
  33
  34 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
  35
  36
  37 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
  38
  39 //- Construct from matrix and solver data stream
  40 template<class Type>
  41 Foam::BlockAmgSolver<Type>::BlockAmgSolver
  42 (
  43     const word& fieldName,
  44     const BlockLduMatrix<Type>& matrix,
  45     const dictionary& dict
  46 )
  47 :
  48     BlockIterativeSolver<Type>
  49     (
  50         fieldName,
  51         matrix,
  52         dict
  53     ),
  54     amg_
  55     (
  56         matrix,
  57         dict
  58     )
  59 {}
  60
  61
  62 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
  63
  64 template<class Type>
  65 typename Foam::BlockSolverPerformance<Type>
  66 Foam::BlockAmgSolver<Type>::solve
  67 (
  68     Field<Type>& x,
  69     const Field<Type>& b
  70 )
  71 {
  72     // Prepare solver performance
  73     BlockSolverPerformance<Type> solverPerf
  74     (
  75         typeName,
  76         this->fieldName()
  77     );
  78
  79     // Create local references to avoid the spread this-> ugliness
  80     const BlockLduMatrix<Type>& matrix = this->matrix_;
  81
  82     scalar norm = this->normFactor(x, b);
  83
  84     Field<Type> wA(x.size());
  85
  86     // Calculate residual.  Note: sign of residual swapped for efficiency
  87     matrix.Amul(wA, x);
  88     wA -= b;
  89
  90     solverPerf.initialResidual() = gSum(cmptMag(wA))/norm;
  91     solverPerf.finalResidual() = solverPerf.initialResidual();
  92
  93     if (!solverPerf.checkConvergence(this->tolerance(), this->relTolerance()))
  94     {
  95         do
  96         {
  97             amg_.cycle(x, b);
  98
  99             // Re-calculate residual.  Note: sign of residual swapped
 100             // for efficiency
 101             matrix.Amul(wA, x);
 102             wA -= b;
 103
 104             solverPerf.finalResidual() = gSum(cmptMag(wA))/norm;
 105             solverPerf.nIterations()++;
 106
 107         } while (!this->stop(solverPerf));
 108     }
 109
 110     return solverPerf;
 111 }
 112
 113
 114 // ************************************************************************* //