function [int, persist, transient] = compute_interface_nodes(intra, inter)% COMPUTE_INTERFACE_NODES Find the nodes in a DBN that represent a sufficient statistic% [int, persist, transient] = compute_interface_nodes(intra, inter)%% The interface nodes are all those that has an incoming temporal arc,% or which have a child which has an incoming temporal arc,% where a temporal arc means one coming from the previous slice.% (The parents of nodes with incoming temporal arcs are needed% because moralization will bring them into the clique.)%% The persisent nodes are all those that have one or more incoming temporal arc.% The transient nodes are all the non-persistent.%% See U. Kjaerulff, "dHugin: A computational system for dynamic% time-sliced Bayesian networks", Intl. J. Forecasting (11) 89-111, 1995n = length(intra);int = [];persist = [];for u=1:n  if any(inter(:,u))    int = [int u];    persist = [persist u];  end  if any(inter(:, children(intra, u)))    int = [int u];  endendint = unique(int);persist = unique(persist);transient = mysetdiff(1:n, persist);