LMSCanceller.cpp

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#include "LMSCanceller.h"
#include "CFatalException.h"
#include <iostream>
#include <iterator>
using namespace std;

LMSCanceller::LMSCanceller(const int inputsize):
LSSOFilter(inputsize),
mu(1)
{
}

LMSCanceller::LMSCanceller(const int inputsize, const double Mymu):
LSSOFilter(inputsize),
mu(Mymu)
{
}

LMSCanceller::~LMSCanceller()
{}

void LMSCanceller::AdaptFilter(const gplib::rvec &Input, const gplib::rvec &Desired)
{
        if (Input.size() != GetInputLength() || Input.size() != Weights.size() || Desired.size() != GetOutputLength())
                throw CFatalException("Input or Desired do not have expected size !");
        
        SetEpsilon(Desired - GetFilterOutput()); //Calculate the last prediction error
        double step = ublas::prec_inner_prod(Input,Input); //the power of the input data
        const double delta = 0.0001; // We introduce delta to improve stability for small values
        step = mu/(step+delta);  //here see Haykin, p 323
        Weights += 2.0 * step * GetEpsilon()(0) * Input; //update Filter based on prediction error
}

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