HillOptimizer.hpp

//HillOptimizer.hpp
// Created on: June 3, 2015
//     Author: Hafez Farazi <farazi@ais.uni-bonn.de>
#pragma once
#include "opencv2/opencv.hpp"
#include <stdlib.h>     /* abs */
#include <vision_module/Tools/General.hpp>
#include <vision_module/Tools/OptimizorParam.hpp>

using namespace cv;
template<class T>
class HillOptimizer
{
private:
    vector<OptimizorParam> parameters;
    unsigned int paramsCount;
    T& obj;
    float (T::*pFunc)(const vector<OptimizorParam>& parameters);
public:
    HillOptimizer(T& obj, float (T::*pFunc)(const vector<OptimizorParam>& parameters)) :
        paramsCount(0),obj(obj), pFunc(pFunc)
    {

    }

    bool TuneForBest(int maxIteration, double tol = 0.0000001)
    {
        double lastRes = Tune();
        cout << " First Tune =" << lastRes << endl;
        int successCounter = 0;
        for (int i = 0; i < maxIteration; i++)
        {
            double curRes = Tune();
            cout << " Tune counter = " << i << " TuneRes = " << curRes << endl;
            if ((lastRes - curRes) < tol)
            {
                successCounter++;
            }
            else
            {
                successCounter = 0;
            }
            if (successCounter >= 3)
            {
                return true;
            }
            lastRes = curRes;
        }
        return false;
    }

    float Tune()
    {
        float bestResult = 999999999;
        for (size_t i = 0; i < paramsCount; i++)
        {
            float resOld = (obj.*pFunc)(parameters);
            float resAbove = resOld;
            float resBelow = resOld;

            bool tuned = false;
            while (!tuned)
            {
                float oldParameter = parameters[i].data;

                float stepAbove = oldParameter + parameters[i].step;
                float stepBelow = oldParameter - parameters[i].step;

                parameters[i].data = stepAbove;
                resAbove = (obj.*pFunc)(parameters);

                parameters[i].data = stepBelow;
                resBelow = (obj.*pFunc)(parameters);

                if (resAbove < resBelow && resAbove < resOld)
                {
                    parameters[i].data = stepAbove;
                    resOld = resAbove;
                }
                else if (resAbove > resBelow && resBelow < resOld)
                {
                    parameters[i].data = stepBelow;
                    resOld = resBelow;
                }
                else
                {
                    parameters[i].data = oldParameter;
                    bestResult = min(bestResult, resOld);
                    tuned = true;
                }
            }
        }
        return bestResult;
    }

    void setParameters(vector<OptimizorParam> _parameters)
    {
        parameters = _parameters;
        paramsCount = _parameters.size();
    }
    vector<OptimizorParam> getParameters() const
    {
        return parameters;
    }
};