radial distance definition
Radial Distance is a brute force O(n) algorithm for polyline simplification. It reduces successive vertices that are clustered too closely to a single vertex, called a key. The resulting keys form the simplified polyline. This process is illustrated below: The first and last vertices are always part of the simplification, and are thus marked as keys. Starting at the first key (the first vertex), the algorithm walks along the polyline. All consecutive vertices that fall within a specified distance tolerance from that key are removed.