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fft.H

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00001 /*---------------------------------------------------------------------------*\
00002   =========                 |
00003   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
00004    \\    /   O peration     |
00005     \\  /    A nd           | Copyright (C) 1991-2005 OpenCFD Ltd.
00006      \\/     M anipulation  |
00007 -------------------------------------------------------------------------------
00008 License
00009     This file is part of OpenFOAM.
00010 
00011     OpenFOAM is free software; you can redistribute it and/or modify it
00012     under the terms of the GNU General Public License as published by the
00013     Free Software Foundation; either version 2 of the License, or (at your
00014     option) any later version.
00015 
00016     OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
00017     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
00018     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
00019     for more details.
00020 
00021     You should have received a copy of the GNU General Public License
00022     along with OpenFOAM; if not, write to the Free Software Foundation,
00023     Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
00024 
00025 Global
00026     fft
00027 
00028 Description
00029     Fast fourier transform subroutine derived from the Numerical
00030     Recipes in C routine.  The complex transform field is returned
00031     in the field supplied.  The direction of transform is supplied
00032     as an argument (1 = forward, -1 = reverse).  The dimensionality
00033     and organisation of the array of values in space is supplied
00034     in the nn indexing array.
00035 
00036 SourceFiles
00037     fft.C
00038 
00039 \*---------------------------------------------------------------------------*/
00040 
00041 #ifndef fft_H
00042 #define fft_H
00043 
00044 #include "complexFields.H"
00045 #include "labelList.H"
00046 
00047 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
00048 
00049 namespace Foam
00050 {
00051 
00052 class fft
00053 {
00054 
00055 public:
00056 
00057     enum transformDirection
00058     {
00059         FORWARD_TRANSFORM = 1,
00060         REVERSE_TRANSFORM = -1
00061     };
00062 
00063 
00064     static void transform
00065     (
00066         complexField& field,
00067         const labelList& nn,
00068         transformDirection fftDirection
00069     );
00070 
00071 
00072     static tmp<complexField> forwardTransform
00073     (
00074         const tmp<complexField>& field,
00075         const labelList& nn
00076     );
00077 
00078 
00079     static tmp<complexField> reverseTransform
00080     (
00081         const tmp<complexField>& field,
00082         const labelList& nn
00083     );
00084 
00085 
00086     static tmp<complexVectorField> forwardTransform
00087     (
00088         const tmp<complexVectorField>& field,
00089         const labelList& nn
00090     );
00091 
00092 
00093     static tmp<complexVectorField> reverseTransform
00094     (
00095         const tmp<complexVectorField>& field,
00096         const labelList& nn
00097     );
00098 };
00099 
00100 
00101 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
00102 
00103 } // End namespace Foam
00104 
00105 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
00106 
00107 #endif
00108 
00109 // ************************************************************************* //
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