src/POD/PODOrthoNormalBase/scalarPODOrthoNormalBase.C

   1 /*---------------------------------------------------------------------------*\
   2   =========                 |
   3   \\      /  F ield         | foam-extend: Open Source CFD
   4    \\    /   O peration     | Version:     3.2
   5     \\  /    A nd           | Web:         http://www.foam-extend.org
   6      \\/     M anipulation  | For copyright notice see file Copyright
   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 Class
  25     PODOrthoNormalBase
  26
  27 Description
  28     Establish POD ortho-normal base and interpolation coefficients give a list
  29     of fields. Size of ortho-normal base is calculated from the desired
  30     accuracy, e.g. 0.99-0.99999 (in energy terms)
  31
  32 \*---------------------------------------------------------------------------*/
  33
  34 #include "scalarPODOrthoNormalBase.H"
  35 #include "PODEigenBase.H"
  36 #include "IOmanip.H"
  37 #include "zeroGradientFvPatchFields.H"
  38
  39 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
  40
  41 template<>
  42 void Foam::PODOrthoNormalBase<Foam::scalar>::calcOrthoBase
  43 (
  44     const PtrList<volScalarField>& snapshots,
  45     const scalar accuracy
  46 )
  47 {
  48     PODEigenBase eigenBase(snapshots);
  49
  50     label baseSize = 0;
  51
  52     const scalarField& cumEigenValues = eigenBase.cumulativeEigenValues();
  53
  54     forAll (cumEigenValues, i)
  55     {
  56         baseSize++;
  57
  58         if (cumEigenValues[i] > accuracy)
  59         {
  60             break;
  61         }
  62     }
  63
  64     Info<< "Cumulative eigen-values: "
  65         << setprecision(14) << cumEigenValues << nl
  66         << "Base size: " << baseSize << endl;
  67
  68     // Establish orthonormal base
  69     orthoFields_.setSize(baseSize);
  70
  71     for (label baseI = 0; baseI < baseSize; baseI++)
  72     {
  73         const scalarField& eigenVector = eigenBase.eigenVectors()[baseI];
  74
  75         volScalarField* onBasePtr
  76         (
  77             new volScalarField
  78             (
  79                 IOobject
  80                 (
  81                     snapshots[0].name() + "POD" + name(baseI),
  82                     snapshots[0].time().timeName(),
  83                     snapshots[0].mesh(),
  84                     IOobject::NO_READ,
  85                     IOobject::NO_WRITE
  86                 ),
  87                 snapshots[0].mesh(),
  88                 dimensionedScalar("zero", snapshots[0].dimensions(), 0)
  89             )
  90         );
  91         volScalarField& onBase = *onBasePtr;
  92
  93         forAll (eigenVector, eigenI)
  94         {
  95             onBase += eigenVector[eigenI]*snapshots[eigenI];
  96         }
  97
  98         // Re-normalise ortho-normal vector
  99         scalar magSumSquare = Foam::sqrt(sumSqr(onBase));
 100         if (magSumSquare > SMALL)
 101         {
 102             onBase /= magSumSquare;
 103             onBase.correctBoundaryConditions();
 104         }
 105
 106         orthoFields_.set(baseI, onBasePtr);
 107     }
 108
 109     // Calculate interpolation coefficients
 110     interpolationCoeffsPtr_ =
 111         new RectangularMatrix<scalar>(snapshots.size(), orthoFields_.size());
 112     RectangularMatrix<scalar>& coeffs = *interpolationCoeffsPtr_;
 113
 114     forAll (snapshots, snapshotI)
 115     {
 116         forAll (orthoFields_, baseI)
 117         {
 118             coeffs[snapshotI][baseI] =
 119                 POD::projection
 120                 (
 121                     snapshots[snapshotI],
 122                     orthoFields_[baseI]
 123                 );
 124         }
 125     }
 126 }
 127
 128
 129 // ************************************************************************* //