wolffd@0: function fg = mk_fgraph_given_ev(G, node_sizes, factors, ev_CPD, evidence, varargin) wolffd@0: % MK_FGRAPH_GIVEN_EV Make a factor graph where each node has its own private evidence term wolffd@0: % fg = mk_fgraph(G, node_sizes, factors, ev_CPD, evidence, ...) wolffd@0: % wolffd@0: % G, node_sizes and factors are as in mk_fgraph, but they refer to the hidden nodes. wolffd@0: % ev_CPD{i} is a CPD for the i'th hidden node; this will be converted into a factor wolffd@0: % for node i using evidence{i}. wolffd@0: % We currently assume all hidden nodes are discrete, for simplicity. wolffd@0: % wolffd@0: % The list below gives optional arguments [default value in brackets]. wolffd@0: % wolffd@0: % equiv_class - equiv_class(i)=j means factor node i gets its params from factors{j} [1:F] wolffd@0: % ev_equiv_class - ev_equiv_class(i)=j means evidence node i gets its params from ev_CPD{j} [1:N] wolffd@0: wolffd@0: wolffd@0: N = length(node_sizes); wolffd@0: nfactors = length(factors); wolffd@0: wolffd@0: % default values for parameters wolffd@0: eclass = 1:nfactors; wolffd@0: ev_eclass = 1:N; wolffd@0: wolffd@0: if nargin >= 6 wolffd@0: args = varargin; wolffd@0: nargs = length(args); wolffd@0: for i=1:2:nargs wolffd@0: switch args{i}, wolffd@0: case 'equiv_class', eclass = args{i+1}; wolffd@0: case 'ev_equiv_class', ev_eclass = args{i+1}; wolffd@0: otherwise, wolffd@0: error(['invalid argument name ' args{i}]); wolffd@0: end wolffd@0: end wolffd@0: end wolffd@0: wolffd@0: pot_type = 'd'; wolffd@0: for x=1:N wolffd@0: ev = cell(1,2); % cell 1 is the hidden parent, cell 2 is the observed child wolffd@0: ev(2) = evidence(x); wolffd@0: dom = 1:2; wolffd@0: F = convert_to_pot(ev_CPD{ev_eclass(x)}, pot_type, dom(:), ev); wolffd@0: M = pot_to_marginal(F); wolffd@0: %factors{end+1} = tabular_CPD('self', 1, 'ps', [], 'sz', node_sizes(x), 'CPT', M.T); wolffd@0: factors{end+1} = mk_isolated_tabular_CPD(node_sizes(x), {'CPT', M.T}); wolffd@0: end wolffd@0: wolffd@0: E = max(eclass); wolffd@0: fg = mk_fgraph([G eye(N)], node_sizes, factors, 'equiv_class', [eclass E+1:E+N]);