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NekFFTW.h
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1 ///////////////////////////////////////////////////////////////////////////////
2 //
3 // File NekFFTW.h
4 //
5 // For more information, please see: http://www.nektar.info
6 //
7 // The MIT License
8 //
9 // Copyright (c) 2006 Division of Applied Mathematics, Brown University (USA),
10 // Department of Aeronautics, Imperial College London (UK), and Scientific
11 // Computing and Imaging Institute, University of Utah (USA).
12 //
13 // License for the specific language governing rights and limitations under
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31 //
32 // Description: Header file for the wrapper around FFTW library
33 //
34 ///////////////////////////////////////////////////////////////////////////////
35 
36 #ifndef NEKTAR_LIB_UTILIITIES_FFT_NEKFFTW_H
37 #define NEKTAR_LIB_UTILIITIES_FFT_NEKFFTW_H
38 
40 
46 
47 #include <fftw3.h>
48 
49 namespace Nektar
50 {
51  template <typename Dim, typename DataType>
52  class Array;
53 
54  namespace LibUtilities
55  {
56  class NekFFTW;
57 
58  // A shared pointer to the NekFFTW object
59  typedef boost::shared_ptr<NekFFTW> NekFFTWSharedPtr;
60 
61  class NekFFTW: public NektarFFT
62  {
63  public:
64 
65  /// Creates an instance of this class
66  static NektarFFTSharedPtr create(int N)
67  {
69  }
70 
71  /// Name of class
72  static std::string className;
73 
74  // constructor (initialisation of the FFTW planes and fill up the m_FFTW_w vector)
75  NekFFTW(int N);
76 
77  // Distructor
78  virtual ~NekFFTW();
79 
80 
81 
82  virtual void v_FFTFwdTrans(Array<OneD,NekDouble> &inarray, Array<OneD,NekDouble> &outarray);
83 
84  virtual void v_FFTBwdTrans(Array<OneD,NekDouble> &inarray, Array<OneD,NekDouble> &outarray);
85 
86 
87 
88  protected:
89 
90  Array<OneD,NekDouble> m_FFTW_w; // weights to convert arrays form Nektar++ to FFTW format
91  Array<OneD,NekDouble> m_FFTW_w_inv; // weights to convert arrays from FFTW to Nektar++ format
92 
93  Array<OneD,NekDouble> phys;
94  Array<OneD,NekDouble> coef;
95 
96  Array<OneD,NekDouble> m_wsp; // Workspace area for transforms
97 
98  fftw_plan plan_backward; // plan to execute a backward FFT in FFTW
99  fftw_plan plan_forward; // plan to execute a forward FFT in FFTW
100  /**
101  * Reshuffling routines to put the coefficients in Nektar++/FFTW format.
102  * The routines take as an input the number of points N, the vector of coeffcients
103  * and the vector containing the weights of the numerical integration.
104  * The routines modify directly the coef vector.
105  */
106  void Reshuffle_FFTW2Nek(Array<OneD,NekDouble> &coef);
107 
108  void Reshuffle_Nek2FFTW(Array<OneD,NekDouble> &coef);
109 
110 
111 
112  private:
113  };
114 
115  }//end namespace LibUtilities
116 }//end of namespace Nektar
117 #endif //NEKTAR_LIB_UTILIITIES_FFT_NEKFFTW_H