ABSTRACT
There is an equivalent way of thinking about the positions of the profile points in the profile space, and this will be useful to our eventual understanding and interpretation of CA. This is based on the notion of a weighted average, or centroid, of a set of points. In the calculation of an ordinary (unweighted) average, each point receives equal weight, whereas a weighted average allows different weights to be associated with each point. When the points are weighted differently, then the centroid does not lie exactly at the “geographical” centre of the cloud of points, but tends to lie in a position closer to the points with higher weight.
