Clustering

The cumulant expansion and the linked cluster theorem make it clear that we may cluster in various ways. In the linked cluster theorem we have clustered by the number of variables involved (vertices of a graph). We might also consider clustering by the types of variables involved (support), or by the types of functions involved (functions of arguments within certain sets of variables, say). If we cluster by support then we have an expansion which is useful in defining hierarchical decompositions of functions, as seen in the next section.
 

Tue Mar 25 08:11:49 CST 1997