boltzman.h

/*
 * The GURLS Package in C++
 *
 * Copyright (C) 2011-1013, IIT@MIT Lab
 * All rights reserved.
 *
 * authors:  M. Santoro
 * email:   msantoro@mit.edu
 * website: http://cbcl.mit.edu/IIT@MIT/IIT@MIT.html
 *
 * 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(s) of the copyright holders nor the names
 *       of its contributors or of the Massacusetts Institute of
 *       Technology or of the Italian Institute of Technology 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
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 */


#ifndef _GURLS_CONFBOLTZMAN_H_
#define _GURLS_CONFBOLTZMAN_H_


#include "gurls++/confidence.h"
#include "gurls++/gmath.h"

namespace gurls {

template <typename T>
class ConfBoltzman: public Confidence<T>
{
public:
    GurlsOptionsList* execute(const gMat2D<T>& X, const gMat2D<T>& Y, const GurlsOptionsList& opt) throw(gException);
};

template<typename T>
GurlsOptionsList *ConfBoltzman<T>::execute(const gMat2D<T>& /*X*/, const gMat2D<T>& /*Y*/, const GurlsOptionsList &opt) throw(gException)
{
    //   out = struct;
    //   [n,k] = size(opt.pred);
    const gMat2D<T> &pred = opt.getOptValue<OptMatrix<gMat2D<T> > >("pred");

    const unsigned long n = pred.rows();
    const unsigned long t = pred.cols();


//    expscores = exp(opt.pred);
//    expscores = expscores./(sum(expscores,2)*ones(1,k));
//    [out.confidence, out.labels] = max(expscores,[],2);

    const T* expscores = pred.getData();

    T sum;
    T* rowT = new T[t];

    gMat2D<T> *conf = new gMat2D<T>(n,1);
    T* confidence = conf->getData();

    gMat2D<T> *lab = new gMat2D<T>(n,1);
    T* labels = lab->getData();

    //TODO optmize search of two maxes
    for(unsigned long i=0; i<n; ++i)
    {
        getRow(expscores, n, t, i, rowT);
        exp(rowT, t);

        sum = sumv(rowT, t);
        scal(t, (T)(1.0/sum), rowT, 1);

        int index = static_cast<int>(std::max_element(rowT, rowT+t) - rowT);
        confidence[i] = rowT[index];
        labels[i] = index+1;
    }

    delete [] rowT;

    GurlsOptionsList* ret = new GurlsOptionsList("confidence");

    ret->addOpt("confidence", new OptMatrix<gMat2D<T> >(*conf));
    ret->addOpt("labels", new OptMatrix<gMat2D<T> >(*lab));

    return ret;
}

}

#endif //_GURLS_CONFBOLTZMAN_H_