Well of course it can.
Any set of points can be.
Let us remind ourselves of the elementary methods of doing so. Let be a set of M points in . To say more about the set we proceed to the second order moments. These are the average values of the terms in the given vectors, and there are n 2 of them, so we arrange them in an n by n matrix called the covariance matrix . Here we have not subtracted off one of the points, we have subtracted off of each of them.