/home/marsyas/marsyas/src/marsyas/Metric2.cpp

/*
** Copyright (C) 1998-2006 George Tzanetakis <gtzan@cs.uvic.ca>
**  
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
** 
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
** 
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software 
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

// Coded by Emiru Tsunoo
// 8 SEP. 2008
#include "Metric2.h"
#include "NumericLib.h"

using std::ostringstream;
using namespace Marsyas;

Metric2::Metric2(mrs_string name):MarSystem("Metric2", name)
{
    addControls();
}

Metric2::Metric2(const Metric2& a) : MarSystem(a)
{
    ctrl_metric_ = getctrl("mrs_string/metric");
    ctrl_covMatrix_ = getctrl("mrs_realvec/covMatrix");
}

Metric2::~Metric2()
{

}

MarSystem* 
Metric2::clone() const 
{
    return new Metric2(*this);
}

void 
Metric2::addControls()
{
    addControl("mrs_string/metric", "euclideanDistance", ctrl_metric_);
    ctrl_metric_->setState(true);

    addControl("mrs_realvec/covMatrix", realvec(), ctrl_covMatrix_);
}

void
Metric2::myUpdate(MarControlPtr sender)
{
    (void) sender;
    if(inSamples_ > 1)
        MRSWARN("Metric2::myUpdate - inSamples > 1 : only first column will be processed!");
        
    ctrl_onObservations_->setValue(1, NOUPDATE);
    ctrl_onSamples_->setValue(1, NOUPDATE);
    ctrl_osrate_->setValue(ctrl_israte_, NOUPDATE); //[?]
    ctrl_onObsNames_->setValue("metric", NOUPDATE);

    //the input has the two vectors/matrices to process stacked vertically
    if(inObservations_ % 2 != 0)
        MRSWARN("Metric2::myUpdate - input flow controls do not seem to be in a valid format!");
    vec_i_.create(ctrl_inObservations_->to<mrs_natural>()/2, ctrl_inSamples_->to<mrs_natural>());
    vec_j_.create(ctrl_inObservations_->to<mrs_natural>()/2, ctrl_inSamples_->to<mrs_natural>());

    //get the pointer for the correct metric function
    mrs_string metricName = ctrl_metric_->to<mrs_string>(); 
    if(metricName == "euclideanDistance")
    {
        metricFunc_ = &NumericLib::euclideanDistance;
    }
    else if(metricName == "mahalanobisDistance")
    {
        metricFunc_ = &NumericLib::mahalanobisDistance;
    }
    else if(metricName == "cosineDistance")
    {
        metricFunc_ = &NumericLib::cosineDistance;
    }
    else if(metricName == "logLikelihood")
      {
        metricFunc_ = &logLikelihood;
      }
    else
    {
        MRSWARN("Metric2::myUpdate: unsuported metric funtion: " + metricName);
        metricFunc_ = NULL;
    }
}

void 
Metric2::myProcess(realvec& in, realvec& out)
{
    mrs_natural t,o;
    if(metricFunc_)
    {
        //get the two stacked vectors from the input
        for(o=0; o < inObservations_/2; ++o)
        {
            for(t=0; t < inSamples_; ++t)
            {
                vec_i_(o,t) = in(o,t);
                vec_j_(o,t) = in(o+inObservations_/2,t);
            }
        }

        //do the actual metric calculation
        out(0) = metricFunc_(vec_i_, vec_j_, ctrl_covMatrix_->to<mrs_realvec>());
    }
    else
        out(0) = 0; //default output value when no metric is defined
}

mrs_real
Metric2::logLikelihood(const realvec& Vi, const realvec& Vj, const realvec& covMatrix)
{
  mrs_real res1;
  mrs_real res = 0;
  mrs_real log2pi = log(2.0*PI);
  mrs_real logDet;
  if(covMatrix.getSize() == 0)
    {
      for(mrs_natural r=0; r<Vi.getSize(); ++r)
    {
      res1 = Vi(r)-Vj(r);
      res1 *= res1;
      res += res1;
    }
      res = 0.5*res + 0.5*Vi.getSize()*log2pi;
    }
  else
    {
      //logDet = log(covMatrix.det());
      logDet = 0;
      for(mrs_natural r=0; r<Vi.getSize(); ++r)
    {
      res1 = Vi(r)-Vj(r);
      res1 *= res1;
      if(covMatrix(r,r)>0)
        {
          res1 /= covMatrix(r,r);
          logDet += log(covMatrix(r,r));
        }
      res += res1;
    }
      res = 0.5*res + 0.5*(Vi.getSize()*log2pi+logDet);
    }
  return res;
}

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