function [time, engine] = cmp_inference_dbn(bnet, engine, T, varargin)% CMP_INFERENCE_DBN Compare several inference engines on a DBN% function [time, engine] = cmp_inference_dbn(bnet, engine, T, ...)%% engine{i} is the i'th inference engine.% time(e) = elapsed time for doing inference with engine e%% The list below gives optional arguments [default value in brackets].%% exact - specifies which engines do exact inference [ 1:length(engine) ]% singletons_only - if 1, we only call marginal_nodes, else this  and marginal_family [0]% check_ll - 1 means we check that the log-likelihoods are correct [1]% set default paramsexact = 1:length(engine);singletons_only = 0;check_ll = 1;onodes = bnet.observed;args = varargin;nargs = length(args);for i=1:2:nargs  switch args{i},   case 'exact', exact = args{i+1};   case 'singletons_only', singletons_only = args{i+1};   case 'check_ll', check_ll = args{i+1};   case 'observed', onodes = args{i+1};   otherwise,    error(['unrecognized argument ' args{i}])  endendE = length(engine);ref = exact(1); % referencess = length(bnet.intra);ev = sample_dbn(bnet, 'length', T);evidence = cell(ss,T);evidence(onodes,:) = ev(onodes, :);for i=1:E  tic;  [engine{i}, ll(i)] = enter_evidence(engine{i}, evidence);  time(i)=toc;  fprintf('engine %d took %6.4f seconds\n', i, time(i));endcmp = mysetdiff(exact, ref);if check_ll  for i=cmp(:)'    if ~approxeq(ll(ref), ll(i))      error(['engine ' num2str(i) ' has wrong ll'])    end  endendllhnodes = mysetdiff(1:ss, onodes);if ~singletons_only  get_marginals(engine, hnodes, exact, 0, T);endget_marginals(engine, hnodes, exact, 1, T);%%%%%%%%%%function get_marginals(engine, hnodes, exact, singletons, T)bnet = bnet_from_engine(engine{1});N = length(bnet.intra);cnodes_bitv = zeros(1,N);cnodes_bitv(bnet.cnodes) = 1;ref = exact(1); % referencecmp = exact(2:end);E = length(engine);m = cell(1,E);for t=1:T  for n=1:N  %for n=hnodes(:)'    for e=1:E      if singletons	m{e} = marginal_nodes(engine{e}, n, t);      else	m{e} = marginal_family(engine{e}, n, t);      end    end    for e=cmp(:)'      assert(isequal(m{e}.domain, m{ref}.domain));      if cnodes_bitv(n) & isfield(m{e}, 'mu') & isfield(m{ref}, 'mu')	wrong = ~approxeq(m{ref}.mu, m{e}.mu) | ~approxeq(m{ref}.Sigma, m{e}.Sigma);      else	wrong = ~approxeq(m{ref}.T(:), m{e}.T(:));      end      if wrong	error(sprintf('engine %d is wrong; n=%d, t=%d, fam=%d', e, n, t, ~singletons))      end    end  endend