autoDoc/HTML/---libBayesian-include-CSquasher-h

    /* -*- mode: c++ -*-
    */
    /*

        GIFT, a flexible content based image retrieval system.
        Copyright (C) 1998, 1999, 2000 CUI, University of Geneva

        This program is free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
        the Free Software Foundation; either version 2 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 General Public License for more details.

        You should have received a copy of the GNU General Public License
        along with this program; if not, write to the Free Software
        Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    */
    #ifndef _CSQUASHER
    #define _CSQUASHER

    #include <functional>

    //
    // in general for squashing: for the case that
    // FARTHER much farther away than CLOSER
    // the probability is supposed to be one
    //

    //the base
    class CSquasher:public unary_function<double,double>{
     protected:
      double mSigma;
     public:
      ///the real squashing function
      virtual double operator()(double inCloser,
    			   double inFarther)const=0;
      ///setting a parameter how much to believe the user
      inline void setSigma(double inSigma){
        mSigma=inSigma;
      }
    };

    class CStandardSquasher:public CSquasher{
     public:
      ///
      virtual double operator()(double inCloser,
    			    double inFarther)const;
    };

    class CDiscreteSquasher:public CSquasher{
     public:
      virtual double operator()(double inCloser,
    			    double inFarther)const;
    };

    class CGaussianSquasher:public CSquasher{
     public:
      virtual double operator()(double inCloser,
    			    double inFarther)const;
    };

    class CFlexibleSquasher:public CSquasher{
     public:
      virtual double operator()(double inCloser,
    			    double inFarther)const;
    };

    #endif