complexFFT.H Source File

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# complexFFT.H

    00001 /* Copyright 2001,2002 Matt Flax <flatmax@ieee.org>
    00002    This file is part of the MFFM FFTw Wrapper library.
    00003
    00004    MFFM MFFM FFTw Wrapper library is free software; you can
    00005    redistribute it and/or modify
    00006    it under the terms of the GNU General Public License as published by
    00007    the Free Software Foundation; either version 2 of the License, or
    00008    (at your option) any later version.
    00009
    00010    MFFM FFTw Wrapper library is distributed in the hope that it will be useful,
    00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
    00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00013    GNU General Public License for more details.
    00014
    00015    You have received a copy of the GNU General Public License
    00016    along with the MFFM FFTw Wrapper library
    00017 */
    00018 #ifndef COMPLEXFFT_H_
    00019 #define COMPLEXFFT_H_
    00020
    00021 #include <fftw3.h>
    00022
    00023 #ifndef fftw_real
    00024 #define fftw_real double
    00025 #endif
    00026 #define c_re(c) ((c)[0])
    00027 #define c_im(c) ((c)[1])
    00028
    00029 #include <iomanip>
    00030 using namespace std;
    00031
    00032 #define PLANTYPE FFTW_ESTIMATE
    00033
    00034 /// class complexFFTData controls and manipulates complex fft data
    00035 class complexFFTData {
    00036 public:
    00037   /// Specifies the size of the data array
    00038   int size;
    00039   /// the input and output arrays
    00040   fftw_complex *in, *out;
    00041   /// the power_spectrum array
    00042   fftw_real *power_spectrum;
    00043   /// The total power (summed) of the power spectrum as used in the method compPowerSpec
    00044   double totalPower;
    00045
    00046   /// Constructor with all memory to be allocated internally
    00047   complexFFTData(int sz);
    00048   /// Deconstructor
    00049   ~complexFFTData(void);
    00050
    00051   /// Use this to change associated fft data (for fft'ing)
    00052   void switchData(complexFFTData *d);
    00053
    00054   /// Limits the maximum to 'lim' and returns the last fft bin with max
    00055   int limitHalfPowerSpec(double lim);
    00056
    00057   /// Returns the number of elements in the input and output arrays
    00058   int getSize(){return size;}
    00059   //  int getHalfSize(){ if (!(size%2)) return size/2; else return size/2+1;}
    00060
    00061   /// This function computes the power spectrum and returns the max bin
    00062   int compPowerSpec();
    00063   //  int powerSpecDeriv(); // Find the derivative of the power spectrum
    00064 };
    00065
    00066 ///class complexFFT controls fftw plans and executes fwd/inv transforms
    00067 class complexFFT {
    00068   /// The fwd/inv plans
    00069   fftw_plan fwdPlan, invPlan;
    00070   /// Method to create the plans
    00071   void createPlan(void);
    00072   /// Method to destroy the plans
    00073   void destroyPlan(void);
    00074 protected:
    00075   //  int size;
    00076   /// The pointer to the relevant data
    00077   complexFFTData *data;
    00078 public:
    00079
    00080   //  complexFFT(int sz, char *ws=NULL);
    00081   /// fft init ... data pointed to by 'd'
    00082   complexFFT(complexFFTData *d);
    00083   /// fft deconstructor
    00084   ~complexFFT();
    00085
    00086   /// Use this to change associated fft data (for fft'ing)
    00087   void switchData(complexFFTData *d);
    00088
    00089   /// Forward transform the data (in to out)
    00090   void fwdTransform(); // Forward fft
    00091   /// Inverse transform the data (out to in)
    00092   void invTransform(); // Inverse fft
    00093 };
    00094 /** \example complexFFTExample.cc
    00095  * This is an example of how to use the class.
    00096  */
    00097 #endif // COMPLEXFFT_H_