comparison maths/KLDivergence.cpp @ 31:dfe38135e4c7

* Add cosine distance and the self-similarity matrix used for SB rhythmic
  similarity
* Pull out SB timbral similarity KL divergence into its own file

+/* -*- 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 QMUL
+    All rights reserved.
+*/
+
+#include "KLDivergence.h"
+
+double KLDivergence::distance(const vector<double> &m1,
+			      const vector<double> &v1,
+			      const vector<double> &m2,
+			      const vector<double> &v2)
+{
+    int sz = m1.size();
+
+    double d = -2.0 * sz;
+
+    for (int k = 0; k < sz; ++k) {
+        d += v1[k] / v2[k] + v2[k] / v1[k];
+        d += (m1[k] - m2[k]) * (1.0 / v1[k] + 1.0 / v2[k]) * (m1[k] - m2[k]);
+    }
+
+    d /= 2.0;
+
+    return d;
+}