PitchYin: code cleanup, improve doc (#230)

src/algorithms/tonal/pitchyin.cpp

@@ -26,17 +26,17 @@ using namespace standard;
 
 
 const char* PitchYin::name = "PitchYin";
-const char* PitchYin::description = DOC("This algorithm estimates the fundamental frequency from a given spectrum. It is an implementation of Yin algorithm [1], for computations in the time domain.\n"
+const char* PitchYin::description = DOC("This algorithm estimates the fundamental frequency from a given spectrum. It is an implementation of the Yin algorithm [1] for computations in the time domain.\n"
 "\n"
 "An exception is thrown if an empty signal is provided.\n"
 "\n"
 "Please note that if \"pitchConfidence\" is zero, \"pitch\" is undefined and should not be used for other algorithms.\n"
 "Also note that a null \"pitch\" is never ouput by the algorithm and that \"pitchConfidence\" must always be checked out.\n"
 "\n"
 "References:\n"
-//TODO
-//"  [1] P. M. Brossier, \"Automatic Annotation of Musical Audio for Interactive\n"
-//"  Applications,” QMUL, London, UK, 2007.\n\n"
+"  [1] De Cheveigné, A., & Kawahara, H. \"YIN, a fundamental frequency estimator\n"
+"  for speech and music. The Journal of the Acoustical Society of America,\n"
+"  111(4), 1917-1930, 2002.\n\n"
 "  [2] Pitch detection algorithm - Wikipedia, the free encyclopedia\n"
 "  http://en.wikipedia.org/wiki/Pitch_detection_algorithm");
 
@@ -139,21 +139,6 @@ void PitchYin::compute() {
   // peaks and process the values manually instead of running peak detection 
   // twice and detecting only two peaks. 
 
-  /*
-  for (int tau=1; tau < _yin.size(); ++tau) {
-    if (_yin[ŧau] < _threshold) {
-      // Check if this is a local minima
-      if (tau < _yin.size()-1 && _yin[ŧau] < _yin[tau+1] || tau = _yin.size()-1) {
-        period = tau;
-      }
-    }
-  }
-
-  if(!period) {
-    period = argmin(_yin);  
-  }
-  */
-
   // TODO: how to compute confidence?
   // Aubio computes it as 1 - min(_yin), but this does not correspond to the peak
   // dound by peakDetectLocal

src/algorithms/tonal/pitchyin.h

@@ -35,9 +35,7 @@ class PitchYin : public Algorithm {
   Algorithm* _peakDetectLocal;
   Algorithm* _peakDetectGlobal;
 
-
-  std::vector<Real> _df;          // cumulative mean normalized difference function
-  std::vector<Real> _yin;         // Yin function
+  std::vector<Real> _yin;         // Yin function (cumulative mean normalized difference)
   std::vector<Real> _positions;   // Yin function peak positions
   std::vector<Real> _amplitudes;  // Yin function peak amplitudes