File content as of revision 0:a9412b9e85b7:

//--------------------------------------------------------------
// IIR filter ---- Cascade structure
// 2014/10/23, Copyright (c) 2014 MIKAMI, Naoki
//--------------------------------------------------------------

#ifndef IIR_CASCADE_HPP
#define IIR_CASCADE_HPP

#include "mbed.h"
#include "Biquad.hpp"

namespace Mikami
{
    // IIR filter -- Cascade structure
    template<int order> class IirCascade
    {
    private:
        Biquad hk_[order];  // Elements of cascade structure
        float g0_;          // gain factor

        IirCascade(const IirCascade&);
        IirCascade& operator=(const IirCascade&);

    public:
        IirCascade() {}
        IirCascade(float g0, const Biquad::Coefs ck[])
        { SetCoefs(g0, ck); }

        void SetCoefs(float g0, const Biquad::Coefs ck[])
        {
            g0_ = g0;
            for (int k=0; k<order; k++)
                hk_[k] = Biquad(ck[k]);
        }

        float Execute(float xn)
        {
            float yn = g0_*xn;
            for (int k=0; k<order; k++)
                yn = hk_[k].Execute(yn);
                
            return yn;
        }
        
        void Clear()
        {
            for (int k=0; k<order; k++)
                hk_[k].Clear();
        }
    };
}
#endif  // IIR_CASCADE_HPP