view CITATION @ 10:af59167b3d35 perf

size_t -> int throughout: permits better optimisation for tight for-loops, making the whole thing about 10% faster

@inproceedings{luis2012a,
  author = {Luis Jure and Ernesto López and Martín Rocamora and Pablo Cancela and Haldo Sponton and Ignacio Irigaray},
  title = {Pitch Content Visualization Tools for Music Performance Analysis},
  booktitle = {Proceedings of the 13th International Society for Music Information Retrieval Conference (ISMIR 2012)},
  year = {2012}
}