comparison toolboxes/FullBNT-1.0.7/bnt/general/Old/mk_gdl_graph.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function gdl = mk_gdl_graph(G, domains, node_sizes, kernels, varargin)
+% MK_GDL_GRAPH Make a GDL (generalized distributed law) graph
+% gdl = mk_gdl_graph(G, domains, node_sizes, kernels, ...)
+%
+% A GDL graph is like a moralized, but untriangulated, Bayes net:
+% each "node" represents a domain with a corresponding kernel function.
+% For details, see "The Generalized Distributive Law", Aji and McEliece,
+% IEEE Trans. Info. Theory, 46(2): 325--343, 2000
+% 
+% G(i,j) = 1 if there is an (undirected) edge between domains i,j
+%
+% domains{i} is the domain of node i
+%
+% node_sizes(i) is the number of values node i can take on,
+%   or the length of node i if i is a continuous-valued vector.
+% node_sizes(i) = 1 if i is a utility node.
+%
+% kernels is the list of kernel functions
+%
+% The list below gives optional arguments [default value in brackets].
+% 
+% equiv_class - equiv_class(i)=j  means factor node i gets its params from factors{j} [1:F]
+% discrete - the list of nodes which are discrete random variables [1:N]
+% chance   - the list of nodes which are random variables [1:N]
+% decision - the list of nodes which are decision nodes [ [] ]
+% utility  - the list of nodes which are utility nodes [ [] ]
+
+
+ns = node_sizes;
+N = length(domains);
+vars = [];
+for i=1:N
+  vars = myunion(vars, domains{i});
+end
+Nvars  = length(vars);
+
+gdl.equiv_class = 1:length(kernels);
+gdl.chance_nodes = 1:Nvars;
+gdl.utility_nodes = [];
+gdl.decision_nodes = [];
+gdl.dnodes = 1:Nvars;
+
+if nargin >= 5
+  args = varargin;
+  nargs = length(args);
+  for i=1:2:nargs
+    switch args{i},
+     case 'equiv_class', bnet.equiv_class = args{i+1}; 
+     case 'chance',      bnet.chance_nodes = args{i+1}; 
+     case 'utility',     bnet.utility_nodes = args{i+1}; 
+     case 'decision',    bnet.decision_nodes = args{i+1}; 
+     case 'discrete',    bnet.dnodes = args{i+1}; 
+     otherwise,  
+      error(['invalid argument name ' args{i}]);       
+    end
+  end
+end
+
+
+gdl.G = G;
+gdl.vars = vars;
+gdl.doms = domains;
+gdl.node_sizes = node_sizes;
+gdl.cnodes = mysetdiff(vars, gdl.dnodes);
+gdl.kernels = kernels;
+gdl.type = 'gdl';
+
+% Compute a bit vector representation of the set of domains
+% dom_bitv(i,j) = 1 iff variable j occurs in domain i
+gdl.dom_bitv = zeros(N, length(vars));
+for i=1:N
+  gdl.dom_bitv(i, domains{i}) = 1;
+end
+
+% compute the interesection of the domains on either side of each edge (separating set)
+gdl.sepset = cell(N, N);
+gdl.nbrs = cell(1,N);
+for i=1:N
+  nbrs = neighbors(G, i);
+  gdl.nbrs{i} = nbrs;
+  for j = nbrs(:)'
+    gdl.sepset{i,j} = myintersect(domains{i}, domains{j});
+  end
+end
+
+