normaliz.h

Go to the documentation of this file.

/*

Copyright (c) 2003, Cornell University
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

   - Redistributions of source code must retain the above copyright notice,
       this list of conditions and the following disclaimer.
   - Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.
   - Neither the name of Cornell University nor the names of its
       contributors may be used to endorse or promote products derived from
       this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
THE POSSIBILITY OF SUCH DAMAGE.

*/

#if !defined(_NORMALIZ_H)
#define _NORMALIZ_H

#include <math.h>
#include <string>
#include "general.h"
#include "exceptions.h"

namespace CLUS
{

/** The following structure is used for scaling the inputs and the outputs
     newVal=adit+mult*oldVal.
  The input values are scaled by the data generator when identification is
     in progres and by inference function when we use it.
  This applies also to output variables but infer() treats diferently input
     and output values and the data genetator that contained the training
     data and which computes the scaling factors must take in consideration
     this thing (input scaling computations are diferent from output ones).
 */    
class Scale
{

private:
    double    adit;
    double    mult;
    
public:
    enum NormType { Interval, Distribution };
    NormType    type;

    Scale(Real Ad=0.0, Real Mu=1.0, NormType Type=Interval):adit(Ad),mult(Mu),type(Type)
    { }
    
    inline void SetCoefForInput(double arg1, double arg2, NormType Type)
    {
        type=Type;

        double sigma;

        // can replace the if with case if more than two types
        if (type==Interval)
        {
            // arg1=Min, arg2=Max
            /*adit=-arg1/(arg2-arg1);
              mult=1/(arg2-arg1); */
            // normalize to [-1:1]
            adit=-(arg1+arg2)/(arg2-arg1);
            mult=2.0/(arg2-arg1);
        }
        else
        {
            // arg1=Med, arg2=Med2
            sigma=sqrt(arg2-pow2(arg1));
            adit=-arg1/sigma;
            mult=1/sigma;
        }
    }
    
    inline void SetCoefForOutput(double arg1, double arg2, NormType Type)
    {
        type=Type;
        double sigma;
        
        // can replace the if with case if more than two types
        if (type==Interval)
        {
            // arg1=Min, arg2=Max
            /*adit=arg1;
              mult=(arg2-arg1);*/
            adit=(arg1+arg2)/2.0;
            mult=arg2-adit;
        }
        else
        {
            // arg1=Med, arg2=Med2
            sigma=sqrt(arg2-pow2(arg1));
            adit=arg1;
            mult=sigma;
        }
    }
    
    double Transform(double data) const
    {
        return data*mult+adit;
    }
    
    double InverseTransform (double data) const
    {
        return (data-adit)/mult;
    }

    inline void SaveToStream(ostream& out)
    {
        out << "[ " << adit << " " << mult << " ] ";
    }
    
    inline void LoadFromStream(istream& in)
    {
        string s;
        in >> s;
        if (s!="[")
            throw ErrMsg("[ missing");
            
        in >> adit >> mult;
        in >> s;
        if (s!="]")
            throw ErrMsg("] missing)");
    }
};

}

#endif /* _NORMALIZ_H */

---