Daniel@0: function strong = test_strong_root(jtree,cliques,dnodes,root)
Daniel@0: % This function tests, whether root is a strong root of jtree. 
Daniel@0: % The following parameters are used
Daniel@0: % Input:
Daniel@0: % jtree   An matrix with two colums. jtree(i,j) == jtree(j,i) is 1 if node 
Daniel@0: %         i is connected with node j
Daniel@0: % cliques Cells which contain the nodes in each clique
Daniel@0: % dnodes  An array with the discrete nodes of the juntion tree.
Daniel@0: % root    It is tested whether root is the strong root of the junction tree
Daniel@0: % Output:
Daniel@0: % strong  The output is 1 if root is the strong root of the junction tree jtree.
Daniel@0: %         Please note, that the running intersection property is not tested. 
Daniel@0: if isempty(dnodes)
Daniel@0:      strong = 1;
Daniel@0:      return;
Daniel@0: end
Daniel@0: 
Daniel@0: children = find(jtree(root,:)==1);
Daniel@0: i = 1;
Daniel@0: strong = 1;
Daniel@0: while (i <= length(children)) & (strong==1)
Daniel@0:      child = children(i);
Daniel@0:      jtree(child,root) = 0;
Daniel@0:      jtree(root,child) = 0;
Daniel@0:      sep = myintersect(cliques{child},cliques{root});
Daniel@0:      diff = mysetdiff(cliques{child},cliques{root});
Daniel@0:      if (mysubset(sep,dnodes) | isempty(myintersect(diff,dnodes)))
Daniel@0:          strong = test_strong_root(jtree,cliques,dnodes,child);
Daniel@0:      else
Daniel@0:          strong = 0;
Daniel@0:      end;
Daniel@0:      i = i+1;
Daniel@0: end
Daniel@0: