fir_decim.h

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// 
// Copyright(c) 1993-1996 Tony Kirke
// author="Tony Kirke" *
/*
 * SPUC - Signal processing using C++ - A DSP library
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef FIRD
#define FIRD
#include <fir.h>
namespace SPUC {


template <class Numeric> class fir_decim : public fir<Numeric>
{
 public: 
        fir_decim<Numeric>(void) { }
        fir_decim<Numeric>(long n) : fir<Numeric>(n) {  }
        fir_decim<Numeric>(const char* file) { fir<Numeric>::read_taps(file); }
        
        void input(Numeric in) {
                int i;                                           
                // Update history of inputs
                for (i=fir<Numeric>::num_taps-1;i>0;i--) fir<Numeric>::z[i] = fir<Numeric>::z[i-1];  
                // Add new input
                fir<Numeric>::z[0] = in;   
        }
        Numeric decim(void) {
                // Perform FIR
                Numeric output;
                int i;
                for (output=0,i=0;i<fir<Numeric>::num_taps;i++) output += fir<Numeric>::coeff[i]*fir<Numeric>::z[i];
                return(output); 
        }

};      
} // namespace SPUC 
#endif

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