continuouslineartransformation.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.

*/

// -*- C++ -*-

#if !defined _CLUS_CONTINUOUSLINEARTRANSFORMATION_H
#define _CLUS_CONTINUOUSLINEARTRANSFORMATION_H

#include "vec.h"
#include "cmat.h"
#include <math.h>

using namespace TNT;

namespace CLUS
{

/** Applies linear shifts on continuous data. Keeps track of what
    columns transformations are applied on.
 
    Applying the shift means substracting it from the dataset.
*/
class ContinuousLinearTransformation
{
    /// keep track the attributes
    Vector<bool> mask;

    /// shifts: attributes as rows, datasets as columns
    Matrix<double> shifts;

    /// original dataset; transformations are applied to it when they change
    Matrix<double>& dataset;
    
public:
    ContinuousLinearTransformation(int NoAttributes, int NoDatasets, Matrix<double>& TrainingDataset):
            mask(NoAttributes), shifts(NoAttributes,NoDatasets), dataset(TrainingDataset)
    {
        mask=false;
        shifts=0;
    }

    double getShift(int i, int j)
    {
        assert( mask[i] );
        return shifts[i][j];
    }

    void SetShiftsAttribute(int attrib, Vector<double>& shiftsAtt)
    {
        assert(shiftsAtt.dim()==shifts.num_cols());

        bool isAnyNan=false;

        for (int i=0; i<shifts.num_cols(); i++)
        {
            if (isnan(shiftsAtt[i]))
                isAnyNan=true;

            shifts[attrib][i]=shiftsAtt[i];
        }
        mask[attrib]=true;

        assert(!isAnyNan);

        if (isAnyNan)
            return;
        //cerr <<  " deep in setshiftsattribute" << endl;
        // apply the shift to the attrib column of the data
        for (int i=0; i<dataset.num_rows(); i++)
        {
            int datasetIndex=(int)dataset[i][(int)dataset.num_cols()-1];
            //cerr<<dataset.num_cols();
            //cerr<< " dataset index " << datasetIndex<< endl;
            dataset[i][attrib]=dataset[i][attrib]-shiftsAtt[datasetIndex];
            //cerr <<" attribute " << attrib << endl;
        }
    }

    double GetShift(int attrib, int datasetIndex)
    {
        return shifts[attrib][datasetIndex];
    }

    /** Use the same convention with last position encoding the original dataset */
    void ApplyShiftToTuple(double* dataPoint, int datasetIndex)
    {
        int noAttribs=mask.dim();
        for (int i=0; i<noAttribs; i++)
        {
            dataPoint[i]=dataPoint[i]-shifts[i][datasetIndex];
        }
    }

    bool HasAttributeShifts(int attrib)
    {
        return mask[attrib];
    }
};

}

#endif // _CLUS_CONTINUOUSLINEARTRANSFORMATION_H

---