c@256: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
c@256: 
c@256: /*
c@256:     QM DSP Library
c@256: 
c@256:     Centre for Digital Music, Queen Mary, University of London.
c@256:     This file copyright 2008 QMUL
c@256:     All rights reserved.
c@256: */
c@256: 
c@256: #include "KLDivergence.h"
c@256: 
c@256: double KLDivergence::distance(const vector<double> &m1,
c@256: 			      const vector<double> &v1,
c@256: 			      const vector<double> &m2,
c@256: 			      const vector<double> &v2)
c@256: {
c@256:     int sz = m1.size();
c@256: 
c@256:     double d = -2.0 * sz;
c@256: 
c@256:     for (int k = 0; k < sz; ++k) {
c@256:         d += v1[k] / v2[k] + v2[k] / v1[k];
c@256:         d += (m1[k] - m2[k]) * (1.0 / v1[k] + 1.0 / v2[k]) * (m1[k] - m2[k]);
c@256:     }
c@256: 
c@256:     d /= 2.0;
c@256: 
c@256:     return d;
c@256: }