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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 // ************************************************************************* //