annotate toolboxes/FullBNT-1.0.7/bnt/inference/dynamic/@frontier_inf_engine/marginal_nodes.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
parents
children
rev   line source
wolffd@0 1 function marginal = marginal_nodes(engine, nodes, t)
wolffd@0 2 % MARGINAL_NODES Compute the marginal on the specified query nodes (frontier)
wolffd@0 3 % marginal = marginal_nodes(engine, nodes, t)
wolffd@0 4 %
wolffd@0 5 % 't' specifies the time slice of the earliest node in 'nodes'.
wolffd@0 6 % 'nodes' cannot span more than 2 time slices.
wolffd@0 7 %
wolffd@0 8 % Example:
wolffd@0 9 % Consider a DBN with 2 nodes per slice.
wolffd@0 10 % Then t=2, nodes=[1 3] refers to node 1 in slice 2 and node 1 in slice 3,
wolffd@0 11 % i.e., nodes 3 and 5 in the unrolled network,
wolffd@0 12
wolffd@0 13 if nargin < 3, t = 1; end
wolffd@0 14 assert(length(nodes)==1);
wolffd@0 15 i = nodes(1);
wolffd@0 16 bigpot = engine.fwdback{i,t};
wolffd@0 17 bnet = bnet_from_engine(engine);
wolffd@0 18 ss = length(bnet.intra);
wolffd@0 19 nodes = nodes + (t-1)*ss;
wolffd@0 20 %if t > 1, nodes = nodes + ss; end
wolffd@0 21 marginal = pot_to_marginal(marginalize_pot(bigpot, nodes));