A class useful as a starting point for bag-of-words, TF-IDF, etc. Counter is an informal porting of the Python's collections.Counter class
PHP function that calculates the dot product of two or more vectors. The dot product is the result of multiplying the individual numerical values in two or more vectors.
PHP function that calculates the cosine similarity of two vectors.
Porting of a couple of functions calculating the Jaro and JaroWinkler similarity