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termination.h

Go to the documentation of this file.

#ifndef __TERMINATION_H__
#define __TERMINATION_H__

#include "annetwork.h"

// Externals
class ANNetwork;
class PatternSet;
class Trainer;

class Terminator : public Object {
  public:
                    Terminator          (const PatternSet& validationset, int striplen);
    

    bool            validate            (const ANNetwork& net, Trainer& trainer, int cyclesTrained);

    virtual bool    restore             (ANNetwork& net) {return false;}

    double          generalizationLoss  (double min=-666, double opt=-666) const;

    double          validationError     () const {return mLastValidError;}

    double          minimumError        () const {return mMinValidError;}

    int             howManyTrained      () const {return mMinCycle;}

  protected:
    double  mMinValidError;

    int     mMinCycle;
    
    double  mLastValidError;
    
    const PatternSet& mValidationSet;
    
    int     mStripLength;

    virtual bool    check               (const ANNetwork& net, int cyclesTrained) = 0;

};

Terminator* buildTerminator (const String& modelName,
                             const PatternSet& validationset,
                             int validationInterval);


class TerminatorT800 : virtual public Terminator {
  public:

                    TerminatorT800      (const PatternSet& validationset,
                                         int hits, int striplen);

    bool            check               (const ANNetwork& net, int cyclesTrained);

  protected:
    int         mRaises;
    
    const int   mMaxRaises;
    
};

class DummyTerminator : virtual public Terminator {
  public:

                    DummyTerminator     (const PatternSet& validationset, int striplen) : Terminator (validationset, striplen) {}
    bool            check               (const ANNetwork& net, int cyclesTrained) {mMinCycle = cyclesTrained; return false;}
};

class SavingTerminator : virtual public Terminator {
  public:
                    SavingTerminator    (const PatternSet& validationset, int striplen);
                    ~SavingTerminator   ();

    bool            restore             (ANNetwork& net);

  protected:

    void            save                (const ANNetwork& net, int cyclesTrained);

  private:
    Vector      mBestWeights;
};

// Methods by Lutz Prechelt (prechelt@ira.uka.de). See his article
// "Automatic Early Stopping Using Cross Validation: Quantifying the
// Criteria", 1996.

class GLTerminator : public SavingTerminator {
  public:

                    GLTerminator        (const PatternSet& validationset,
                                         double threshold, int striplen);
    
    bool            check               (const ANNetwork& net, int cyclesTrained);

  protected:
    double  mThreshold;
};

class PRTerminator : public GLTerminator {
  public:
                    PRTerminator        (const PatternSet& validationset, double thrshld,
                                         int striplen, const String& pars);
    
    bool            check               (const ANNetwork& net, int cyclesTrained);

  private:
    int     mStrips;
    double  mGLperP;
    int     mRaises, mMaxRaises;
    bool    mGLFulfilled, mUPFulfilled, mGLperPFulfilled;
    double  mK;
    
    double          progress            (const ANNetwork& net) const;
};

class PQTerminator : public SavingTerminator {
    double  mThreshold;     // Generalization loss threshold for stopping
  public:
                    PQTerminator        (const PatternSet& validationset,
                                         double threshold, int striplen);
    
    bool            check               (const ANNetwork& net, int cyclesTrained);
};

class UPTerminator : public SavingTerminator, public TerminatorT800 {
  public:
                    UPTerminator        (const PatternSet& validationset,
                                         int maxraises, int striplen);

    bool            check               (const ANNetwork& net, int cyclesTrained);
};


#endif

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