Updated NPM dependencies.
Changes ...
Implemented PCC (approximation).
Got rid of the excess loops in the PCC implementation.
A little cleanup ...
More cleanup ...
Got rid of another excess loop in the PCC implementation.
Implemented PCC (exact).
Implemented cosine similarity.
Simple object model changes. BC break: `MinkowskiDistance` now returns `-1` when there are no common scores.
Exported new objects to the main module.
Some readability changes.