/*------------------------------------------------------------------------------*/
/*  NOMAD - Nonlinear Optimization by Mesh Adaptive Direct search -             */
/*          version 3.8.1                                                       */
/*                                                                              */
/*  NOMAD - version 3.8.1 has been created by                                   */
/*                 Charles Audet        - Ecole Polytechnique de Montreal       */
/*                 Sebastien Le Digabel - Ecole Polytechnique de Montreal       */
/*                 Christophe Tribes    - Ecole Polytechnique de Montreal       */
/*                                                                              */
/*  The copyright of NOMAD - version 3.8.1 is owned by                          */
/*                 Sebastien Le Digabel - Ecole Polytechnique de Montreal       */
/*                 Christophe Tribes    - Ecole Polytechnique de Montreal       */
/*                                                                              */
/*  NOMAD v3 has been funded by AFOSR, Exxon Mobil, Hydro Québec, Rio Tinto     */
/*  and IVADO.                                                                  */
/*                                                                              */
/*  NOMAD v3 is a new version of NOMAD v1 and v2. NOMAD v1 and v2 were created  */
/*  and developed by Mark Abramson, Charles Audet, Gilles Couture, and John E.  */
/*  Dennis Jr., and were funded by AFOSR and Exxon Mobil.                       */
/*                                                                              */
/*  Contact information:                                                        */
/*    Ecole Polytechnique de Montreal - GERAD                                   */
/*    C.P. 6079, Succ. Centre-ville, Montreal (Quebec) H3C 3A7 Canada           */
/*    e-mail: nomad@gerad.ca                                                    */
/*    phone : 1-514-340-6053 #6928                                              */
/*    fax   : 1-514-340-5665                                                    */
/*                                                                              */
/*  This program 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 3 of the License, or (at your  */
/*  option) any later version.                                                  */
/*                                                                              */
/*  This program is distributed in the hope that it will be useful, but WITHOUT */
/*  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or       */
/*  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License */
/*  for more details.                                                           */
/*                                                                              */
/*  You should have received a copy of the GNU Lesser General Public License    */
/*  along with this program. If not, see <http://www.gnu.org/licenses/>.        */
/*                                                                              */
/*  You can find information on the NOMAD software at www.gerad.ca/nomad        */
/*------------------------------------------------------------------------------*/


/**
 \file   Pareto_Point.hpp
 \brief  Pareto point (headers)
 \author Sebastien Le Digabel
 \date   2010-04-22
 \see    Pareto_Point.cpp
 */
#ifndef __PARETO_POINT__
#define __PARETO_POINT__

#include "Multi_Obj_Evaluator.hpp"

namespace NOMAD {
    
    /// Pareto point for two objective functions.
    class Pareto_Point : public NOMAD::Set_Element<NOMAD::Eval_Point> {
        
    private:
        
        int _w; ///< Weight.
        
        /// Affectation operator.
        /**
         \param p The right-hand side object -- \b IN.
         */
        Pareto_Point & operator = ( const Pareto_Point & p );
        
    public:
        
        /// Constructor.
        /**
         \param ep A pointer to an evaluation point -- \b IN.
         */
        Pareto_Point ( const NOMAD::Eval_Point * ep )
        : NOMAD::Set_Element<NOMAD::Eval_Point> ( ep ) ,
        _w                                    ( 0  )   {}
        
        /// Copy constructor.
        /**
         \param pp The copied object -- \b IN.
         */
        explicit Pareto_Point ( const Pareto_Point & pp )
        : NOMAD::Set_Element<NOMAD::Eval_Point> ( pp.get_element() ) ,
        _w                                    ( 0                )   {}
        
        /// Destructor.
        virtual ~Pareto_Point ( void ) {}
        
        /// Update the weight.
        /**
         A more evolved formula than \c ++w is used in order
         to avoid stagnation with large number of evaluations.
         */
        void update_w ( void ) { _w = 2 * _w + 2; }
        
        /// Access to the weight.
        /**
         \return The weight.
         */
        int get_w ( void ) const { return _w; }
        
        /// Access to the value of the first objective function.
        /**
         \return The value of the first objective function.
         */
        const NOMAD::Double & get_f1 ( void ) const
        {
            return get_element()->get_bb_outputs()[NOMAD::Multi_Obj_Evaluator::get_i1()];
        }
        
        /// Access to the value of the second objective function.
        /**
         \return The value of the second objective function.
         */
        const NOMAD::Double & get_f2 ( void ) const
        {
            return get_element()->get_bb_outputs()[NOMAD::Multi_Obj_Evaluator::get_i2()];
        }
        
        /// Comparison operator.
        /**
         - Supposes that \c y is a Pareto point.
         - Used for the insertion in a set (the Pareto front).
         - \c f1(*this) and \c f1(y) are compared.
         \param y The right-hand side of the comparison -- \b IN.
         \return A boolean equal to \c true if \c *this \c < \c y.
         */
        virtual bool operator < ( const NOMAD::Set_Element<NOMAD::Eval_Point> & y ) const;
        
        /// Dominance operator.
        /**
         Used for the comparison (dominance) of two Pareto points
         before they are inserted into the Pareto front.
         \param y The right-hand side of the comparison -- \b IN.
         \return A boolean equal to \c true if \c *this dominates \c y.
         */
        bool dominates ( const Pareto_Point & y ) const;
        
        /// Display the Pareto point.
        /**
         \param out The NOMAD::Display object -- \b IN.
         */
        void display ( const NOMAD::Display & out ) const;
    };
    
    /// Display a NOMAD::Pareto_Point object.
    /**
     \param out The NOMAD::Display object -- \b IN.
     \param pp  The NOMAD::Pareto_Point object to be displayed -- \b IN.
     \return    The NOMAD::Display object.
     */
    inline const NOMAD::Display & operator << ( const NOMAD::Display      & out ,
                                               const NOMAD::Pareto_Point & pp    )
    {
        pp.display ( out );
        return out;
    }
}

#endif
