ggreedysearch.h

一个非常有用的开源代码

/*
	Copyright (C) 2006, Mike Gashler

	This library is free software; you can redistribute it and/or
	modify it under the terms of the GNU Lesser General Public
	License as published by the Free Software Foundation; either
	version 2.1 of the License, or (at your option) any later version.

	see http://www.gnu.org/copyleft/lesser.html
*/

#ifndef __GGREEDYSEARCH_H__
#define __GGREEDYSEARCH_H__

#include "GSearch.h"



// At each iteration this algorithm moves in only one
// dimension. If the situation doesn't improve it tries
// the opposite direction. If both directions are worse,
// it decreases the step size for that dimension, otherwise
// it increases the step size for that dimension.
class GMomentumGreedySearch : public GRealVectorSearch
{
protected:
	int m_nDimensions;
	int m_nCurrentDim;
	double* m_pStepSizes;
	double* m_pVector;
	double m_dError;
	double m_dChangeFactor;

public:
	GMomentumGreedySearch(GRealVectorCritic* pCritic);
	virtual ~GMomentumGreedySearch();

	virtual void Iterate();

	// d should be a value between 0 and 1
	void SetChangeFactor(double d) { m_dChangeFactor = d; }
};



// At each iteration this algorithm moves in a random direction
// from the best point ever found. The size of the step is a
// random number raised to a constant power (called the
// conservativeness).
class GStochasticGreedySearch : public GRealVectorSearch
{
protected:
	double m_dRange;
	double m_dConservativeness;
	int m_nDimensions;
	double* m_pVector;
	double* m_pTest;
	double m_dError;

public:
	GStochasticGreedySearch(GRealVectorCritic* pCritic, double dMin, double dRange);
	virtual ~GStochasticGreedySearch();

	virtual void Iterate();

	// d should be greater than 1. A bigger value will cause it to usually
	// take small steps and only rarely take big steps. A smaller value
	// will cause it to take big steps more frequently.
	void SetConservativeness(double d) { m_dConservativeness = d; }
};




class GActionGreedySearch : public GActionPathSearch
{
protected:
	double* m_pTmpState;

public:
	GActionGreedySearch(GActionPathCritic* pCritic);
	virtual ~GActionGreedySearch();

	virtual bool Iterate();
};


#endif // __GGREEDYSEARCH_H__