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Diffstat (limited to 'sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine')
6 files changed, 122 insertions, 0 deletions
diff --git a/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/CVS/Entries b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/CVS/Entries new file mode 100644 index 00000000..a79c7562 --- /dev/null +++ b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/CVS/Entries @@ -0,0 +1,4 @@ +/cond_gauss_inf_engine.m/1.1.1.1/Wed May 29 15:59:56 2002// +/enter_evidence.m/1.1.1.1/Wed May 29 15:59:56 2002// +/marginal_nodes.m/1.1.1.1/Wed May 29 15:59:56 2002// +D diff --git a/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/CVS/Repository b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/CVS/Repository new file mode 100644 index 00000000..41961f94 --- /dev/null +++ b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/CVS/Repository @@ -0,0 +1 @@ +FullBNT/BNT/inference/static/@cond_gauss_inf_engine diff --git a/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/CVS/Root b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/CVS/Root new file mode 100644 index 00000000..f3bd14a6 --- /dev/null +++ b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/CVS/Root @@ -0,0 +1 @@ +:ext:nsaunier@bnt.cvs.sourceforge.net:/cvsroot/bnt diff --git a/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/cond_gauss_inf_engine.m b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/cond_gauss_inf_engine.m new file mode 100644 index 00000000..166ed4cd --- /dev/null +++ b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/cond_gauss_inf_engine.m @@ -0,0 +1,23 @@ +function engine = cond_gauss_inf_engine(bnet) +% COND_GAUSS_INF_ENGINE Conditional Gaussian inference engine +% engine = cond_gauss_inf_engine(bnet) +% +% Enumerates all the discrete roots, and runs jtree on the remaining Gaussian nodes. + +dnodes = mysetdiff(1:length(bnet.dag), bnet.cnodes); + +%onodes = dnodes; % all the discrete ndoes will be observed +%engine.sub_engine = jtree_inf_engine(bnet, onodes); +bnet2 = bnet; +bnet2.observed = dnodes; +engine.sub_engine = jtree_inf_engine(bnet2); + +% This is where we will store the results between enter_evidence and marginal_nodes +engine.T = []; +engine.mu = []; +engine.Sigma = []; +engine.joint_dmarginal = []; +engine.onodes = []; % needed for marginal_nodes +engine.evidence = []; % needed for marginal_nodes add_ev + +engine = class(engine, 'cond_gauss_inf_engine', inf_engine(bnet)); diff --git a/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/enter_evidence.m b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/enter_evidence.m new file mode 100644 index 00000000..db5019b1 --- /dev/null +++ b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/enter_evidence.m @@ -0,0 +1,57 @@ +function [engine, loglik] = enter_evidence(engine, evidence, varargin) +% ENTER_EVIDENCE Add the specified evidence to the network (cond_gauss) +% [engine, loglik] = enter_evidence(engine, evidence, ...) +% +% evidence{i} = [] if if X(i) is hidden, and otherwise contains its observed value (scalar or column vector) + +bnet = bnet_from_engine(engine); +ns = bnet.node_sizes(:); +observed = ~isemptycell(evidence); +onodes = find(observed); +hnodes = find(isemptycell(evidence)); +engine.evidence = evidence; + +% check there are no C->D links where C is hidden +pot_type = determine_pot_type(bnet, onodes); + +dhid = myintersect(hnodes, bnet.dnodes); +S = prod(ns(dhid)); +T = zeros(S,1); + +N = length(bnet.dag); +mu = cell(1,N); +Sigma = cell(1,N); +cobs = myintersect(bnet.cnodes, onodes); +chid = myintersect(bnet.cnodes, hnodes); +ens = ns; +ens(cobs) = 0; +for j=chid(:)' + mu{j} = zeros(ens(j), S); + Sigma{j} = zeros(ens(j), ens(j), S); +end + +for i=1:S + dvals = ind2subv(ns(dhid), i); + evidence(dhid) = num2cell(dvals); + [sub_engine, loglik] = enter_evidence(engine.sub_engine, evidence); + for j=chid(:)' + m = marginal_nodes(sub_engine, j); + mu{j}(:,i) = m.mu; + Sigma{j}(:,:,i) = m.Sigma; + end + T(i) = exp(loglik); +end + +[T, lik] = normalise(T); +loglik = log(lik); + +engine.T = T; +engine.mu = mu; +engine.Sigma = Sigma; + +dnodes = bnet.dnodes; +dobs = myintersect(dnodes, onodes); +ens(dobs) = 1; +engine.joint_dmarginal = dpot(dnodes, ens(dnodes), myreshape(engine.T, ens(dnodes))); + +engine.onodes = onodes; diff --git a/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/marginal_nodes.m b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/marginal_nodes.m new file mode 100644 index 00000000..9c5d60a7 --- /dev/null +++ b/sourcecodes/bnt-master/BNT/inference/static/@cond_gauss_inf_engine/marginal_nodes.m @@ -0,0 +1,36 @@ +function marginal = marginal_nodes(engine, query, add_ev) +% MARGINAL_NODES Compute the marginal on the specified query nodes (cond_gauss) +% marginal = marginal_nodes(engine, query, add_ev) +% +% 'query' must be a singleton set +% add_ev is an optional argument; if 1, we will "inflate" the marginal of observed nodes +% to their original size, adding 0s to the positions which contradict the evidence + +if nargin < 3, add_ev = 0; end + +if length(query) ~= 1 + error('cond_gauss_inf_engine can only handle marginal queries on single nodes') +end +j = query; +bnet = bnet_from_engine(engine); + +if myismember(j, bnet.cnodes) + if ~myismember(j, engine.onodes) + [m, C] = collapse_mog(engine.mu{j}, engine.Sigma{j}, engine.T); + marginal.mu = m; + marginal.Sigma = C; + marginal.T = 1.0; % single mixture component + else + marginal.mu = engine.evidence{j}; + k = bnet.node_sizes(j); + marginal.Sigma = zeros(k,k); + marginal.T = 1.0; % since P(E|E)=1 + end +else + marginal = pot_to_marginal(marginalize_pot(engine.joint_dmarginal, j)); + if add_ev + marginal = add_ev_to_dmarginal(marginal, engine.evidence, bnet.node_sizes); + end +end + +marginal.domain = query; |