RISO is an implementation of heterogeneous, distributed belief
networks in Java. A belief network is a probability model defined on
an acyclic directed graph; distributed means nodes can be on different
hosts, and heterogeneous means allowing different conditional
distributions. The calculations involved are multidimensional
integrations; exact results are known for a catalog of special
cases. If a partial result cannot be calculated as a special case from
the catalog, RISO computes an approximate result by numerical
integration. Partial results are passed from one node in the graph to
another as messages; if nodes live on different hosts, the belief
network is said to be distributed. Messages are passed via RMI. Many
example belief networks and lengthy documents are included in the RISO
release bundle.
