NICE_Optimization/GoldenCutLineSearcher.h

//////////////////////////////////////////////////////////////////////
//
//	GoldenCutLineSearcher.h: interface of the GoldenCutLineSearcher class.
//
//	Written by: Matthias Wacker
//
//////////////////////////////////////////////////////////////////////

#ifndef _GOLDEN_CUT_LINE_SEARCHER_H_
#define _GOLDEN_CUT_LINE_SEARCHER_H_

#include "optimization/LineSearcher.h"
/*!
	class for the golden cut line search

   HowToUse:
	
	  * use setX0() to set the offset
	  * use setH0()	to set the search direction
	  * use setEps() to set the abort criterion
	  * use setBounds() to set a different search bound for lambda than [0,10]
	  * call init()
	  * call optimize() (returns lambda)
 */
class  GoldenCutLineSearcher : public LineSearcher
{
public:

	typedef  LineSearcher	SuperClass;
	typedef  SuperClass::matrix_type matrix_type;
	

	/*!
		default constructor
	*/
	GoldenCutLineSearcher();

	/*!
		constructor
	*/
	GoldenCutLineSearcher(CostFunction *costFunc, OptLogBase *loger);

	/*!
		Copy constructor
		\param opt .. optimizer to copy
	*/
	GoldenCutLineSearcher( const GoldenCutLineSearcher &lin);
	
	/*!
		operator =
	*/
	GoldenCutLineSearcher & operator=(const GoldenCutLineSearcher &lin);

    /*!
		Destructor.
     */
    virtual ~GoldenCutLineSearcher();

	/*!
		set the bound parameters
	*/
	bool setBounds(double c, double d);

	/*!
		set the abort threshold
	*/
	bool setEps(double eps);

	/*!
		optimize
		returns a double..
	*/
	double optimize();

protected:

	/*!
		approximation of the golden cut ratio
	*/
	const double m_fac_a; // = 0.38196601125010515179541316563436;
	
	/*!
		approximation of the golden cut ratio 
	*/
	const double m_fac_b; // = 0,61803398874989484820458683436564;

	/*!
		the bounds
	*/
	double m_c, m_d;

	/*!
		the abort criteria
	*/
	double m_eps;


};

#endif