//////////////////////////////////////////////////////////////////////
//
//	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"

namespace OPTIMIZATION
{
  /*!
    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;


  }; //class
}//namespace

#endif