Landmark point selection

A method comprising:

• receiving data points;
• selecting a first subset of the data points to generate an initial set of landmarks, each data point of the first subset defining a landmark point;
• for each non-landmark data point,
• calculating first data point distances between a respective non-landmark data point and each landmark point of the initial set of landmarks;
• identifying a first shortest data point distance from among the first data point distances between the respective non-landmark data point and each landmark point of the initial set of landmarks;
• and
• storing the first shortest data point distance as a first landmark distance for the respective non-landmark data point;
• identifying a non-landmark data point with a longest first landmark distance in comparison with other first landmark distances of other non-landmark data points;
• and
• adding the non-landmark data point associated with the longest first landmark distance as a first landmark point to the initial set of landmarks to generate an expanded set of landmark points.