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livetrax/libs/qm-dsp/maths/CosineDistance.cpp

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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
/*
QM DSP Library
Centre for Digital Music, Queen Mary, University of London.
This file copyright 2008 Kurt Jacobson.
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. See the file
COPYING included with this distribution for more information.
*/
#include "CosineDistance.h"
#include <iostream>
#include <limits>
using std::cerr;
double CosineDistance::distance(const vector<double> &v1,
const vector<double> &v2)
{
dist = 1.0; dDenTot = 0; dDen1 = 0; dDen2 = 0; dSum1 =0;
double small = 1e-20;
//check if v1, v2 same size
if (v1.size() != v2.size())
{
cerr << "CosineDistance::distance: ERROR: vectors not the same size\n";
return 1.0;
}
else
{
for(unsigned int i=0; i<v1.size(); i++)
{
dSum1 += v1[i]*v2[i];
dDen1 += v1[i]*v1[i];
dDen2 += v2[i]*v2[i];
}
dDenTot = sqrt(fabs(dDen1*dDen2)) + small;
dist = 1-((dSum1)/dDenTot);
return dist;
}
}