1 files changed, 47 insertions, 0 deletions
diff --git a/libs/qm-dsp/maths/CosineDistance.cpp b/libs/qm-dsp/maths/CosineDistance.cpp
new file mode 100644
index 0000000000..13ab9ce0e8
--- /dev/null
+++ b/libs/qm-dsp/maths/CosineDistance.cpp
@@ -0,0 +1,47 @@
+/* -*- 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(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;
+    }
+}