cannam@31: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
cannam@31: 
cannam@31: /*
cannam@31:     QM DSP Library
cannam@31: 
cannam@31:     Centre for Digital Music, Queen Mary, University of London.
cannam@31:     This file copyright 2008 Kurt Jacobson and QMUL.
cannam@31:     All rights reserved.
cannam@31: */
cannam@31: 
cannam@31: #include "BeatSpectrum.h"
cannam@31: 
cannam@31: #include "maths/CosineDistance.h"
cannam@31: 
cannam@31: using std::vector;
cannam@31: 
cannam@31: vector<double> BeatSpectrum::process(const vector<vector<double> > &m)
cannam@31: {
cannam@31:     int origin = 0;
cannam@31:     int sz = m.size()/2;
cannam@31: 
cannam@31:     int i, j, k;
cannam@31: 
cannam@31:     vector<double> v(sz);
cannam@31:     for (i = 0; i < sz; ++i) v[i] = 0.0;
cannam@31: 
cannam@31:     CosineDistance cd;
cannam@31: 
cannam@31:     for (i = origin; i < origin + sz; ++i) {
cannam@31: 
cannam@31:         k = 0;
cannam@31: 
cannam@31:         for (j = i + 1; j < i + sz + 1; ++j) {
cannam@31: 
cannam@31:             v[k++] += cd.distance(m[i], m[j]);
cannam@31:         }
cannam@31:     }
cannam@31: 
cannam@31:     // normalize
cannam@31: 
cannam@31:     double max = 0.0;
cannam@31: 
cannam@31:     for (i = 0; i < sz; ++i) {
cannam@31:         if (v[i] > max) max = v[i];
cannam@31:     }
cannam@31: 
cannam@31:     if (max > 0.0) {
cannam@31:         for (i = 0; i < sz; ++i) {
cannam@31:             v[i] /= max;
cannam@31:         }
cannam@31:     }
cannam@31: 
cannam@31:     return v;
cannam@31: }
cannam@31: