Modernizing K-Nearest Neighbors

The k-nearest neighbors (k-NN) method is one of the oldest statistical/machine learning techniques. It is included in virtually every major package, such as caret, parsnip, mlr3 and scikit-learn. Yet those packages do not go beyond the basics. With today's high-speed computation capability, k-NN can be made much more powerful. Here, we present directions in which that can be done.