classify.h

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#pragma once

/*+
________________________________________________________________________

 (C) dGB Beheer B.V.; (LICENSE) http://opendtect.org/OpendTect_license.txt
 Author:        A.H.Bril
 Date:          Nov 2005
________________________________________________________________________

-*/

#include "generalmod.h"
#include "typeset.h"


template <class T>
mExpClass(General) WeightedClassCounter
{
public:
                WeightedClassCounter( bool canbeneg=true )
                : wts_(0)
                , canbeneg_(canbeneg)           {}

    void        add(int val,T wt=1);

    bool        valid() const                   { return wts_; }
    int         result() const;

    void        clear()                         { delete wts_; wts_ = 0; }

protected:

    bool        canbeneg_;
    TypeSet<T>* wts_;

};


template <class T>
inline void WeightedClassCounter<T>::add( int val, T wt )
{
    const int arridx = !canbeneg_ ? val
                     : (val < 0 ? -1 - 2 * val : 2 * val);
                        // encode 0=>0 -1<=1 1=>2 -2=>3 2=>4 etc.

    if ( !wts_ || wts_->size() <= arridx )
    {
        TypeSet<T>* tmp = wts_ ? new TypeSet<T>( *wts_ ) : 0;
        delete wts_;
        wts_ = new TypeSet<T>( arridx+1, -2. );
        if ( tmp )
            OD::memCopy( wts_->arr(), tmp->arr(), tmp->size() * sizeof(T) );
    }

    T& curwt = (*wts_)[arridx];
    if ( curwt < -1 )
        curwt = wt;
    else
        curwt += wt;
}


template <class T>
inline int WeightedClassCounter<T>::result() const
{
    if ( !valid() ) return 0;

    int winner = -1; T maxwt = -1;
    for ( int idx=0; idx<wts_->size(); idx++ )
    {
        if ( (*wts_)[idx] > maxwt )
            { winner = idx; maxwt = (*wts_)[idx]; }
    }

    int res = winner;
    if ( canbeneg_ )
    {
        // decode 0=>0 1=>-1 2=>1 3=>-2 4=>2 etc.
        res /= 2;
        if ( winner % 2 ) res = -res;
    }
    return res;
}