discretepermutationtransformation.h

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*/

// -*- C++ -*-

#if !defined _CLUS_DISCRETEPERMUTATIONTRANSFORMATION_H
#define _CLUS_DISCRETEPERMUTATIONTRANSFORMATION_H

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

using namespace TNT;
using namespace std;

namespace CLUS
{

/** Permutation[i] is the permuted value of i */
class Permutation
{
    Vector<int> permutation;
public:
    Permutation(): permutation()
    {}

    Permutation(int size): permutation(size)
    {
        for (int i=0; i<size; i++)
            permutation[i]=i;
    }

    Permutation(Vector<int>& auxPermutation):
            permutation(auxPermutation)
    {}

    void RandomizePermutation(int size)
    {
        permutation.newsize(size);

        int curr;
        for (int i =0; i< size; i++)
        {
            curr  = random()%size;
            bool unused = false; // is curr an int that hasn't already been used in the permutation being constructed?

            while (!unused) //find one that hasn't been used
            {
                bool used=false;//flag for !unused in loop below
                curr  = random()%size;
                for(int j =0; j<i; j++)
                {
                    if (permutation[j] == curr)
                        used = true;
                }
                if (!used)
                    unused = true;
                used= false;
            }
            // make curr the  ith entry
            permutation[i] = curr;
        }

    }

    int ApplyInversePermutation(int d)
    {
        // cerr << "in ApplyInverse";
        for (int i=0; i< permutation.size(); i++)
        {
            if (permutation[i]==d)
                return i;
            // else cerr << "found " << permutation[i] << " want "<< d <<endl;
        }
        for (int i=0; i<permutation.size(); i++)
            //cerr << permutation[i] << " ";
            assert(false); //this statement should not be reached.
    }

    void ResetSize(int size)
    {
        permutation.newsize(size);
        for (int i=0; i<size; i++)
            permutation[i]=i;
    }

    int ApplyPermutation(int data)
    {
        //cerr << "permutation size " <<  permutation.size()<<endl;
        return permutation[data];
    }

    void saveToStream(ostream& out)
    {
        for (int i=0; i<permutation.size(); i++)
        {
            out << i << " -> " << permutation[i] << endl;
        }
    }
};

class DiscretePermutationTransformation
{
    /// keep track of the attributes with shifts
    Vector<bool> mask;

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

    /// original dataset; keep arround for dataset information only
    Matrix<double>& cdataset;

    /// discrete dataset; last column ignored since is classlabel
    Matrix<int>& ddataset;
    
    const Vector<int>& dDomainSize;
    
    int numDataSets;

public:
    DiscretePermutationTransformation(int NoAttributes, int NoDatasets,
                                      Matrix<double>& cDataset, Matrix<int>& dDataset,
                                      const Vector<int>& DDomainSize):
            mask(NoAttributes), shifts(NoAttributes,NoDatasets), cdataset(cDataset),
            ddataset(dDataset),dDomainSize(DDomainSize), numDataSets(NoDatasets)
    {
        mask=false;

        for (int i=0; i<NoAttributes; i++)
            for (int j=0; j<numDataSets; j++)
            {
                //   cerr << " (" << i <<", " << j << ") " << DDomainSize[i] << endl;
                (shifts[i][j]).ResetSize(DDomainSize[i]);
            }
    }

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

        for (int i=0; i<shifts.num_cols(); i++)
            shifts[attrib][i]=shiftsAtt[i];
        mask[attrib]=true;
        // cerr << "shifts set";
        // apply the shift to the attrib column of the data
        for (int i=0; i<ddataset.num_rows(); i++)
        {
            int datasetIndex=(int)cdataset[i][cdataset.num_cols()-1];
            //  cerr << " datasetIndex " << datasetIndex << endl;
            //  cerr << " attribute " << attrib << " i " << i << endl;
            if (datasetIndex>0)
                ddataset[i][attrib]=shifts[attrib][datasetIndex].ApplyPermutation(ddataset[i][attrib]);
        }
    }

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

    void ApplyShiftToTuple(int* dataPoint, int datasetIndex)
    {
        int noAttribs=mask.dim();
        for (int i=0; i<noAttribs; i++)
            dataPoint[i]=shifts[i][datasetIndex].ApplyPermutation(dataPoint[i]);
    }

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

    void saveToStream(ostream& out, int attribute, int dataset)
    {
        shifts[attribute][dataset].saveToStream(out);
    }
};

}

#endif // _CLUS_DISCRETEPERMUTATIONTRANSFORMATION_H

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