Indeed. Also, the KNN implementation is rather lightweight. It only has euclidean distance, and basic matrix datastructure. Even just KNN needs several distanc

Indeed. Also, the KNN implementation is rather lightweight. It only has euclidean distance, and basic matrix datastructure. Even just KNN needs several distance metrics built in (manhattan, hamming, mahalonobis, to name a few) and a good ball tree implementation for use on large datasets so that the search time goes from N to log N.