function [engine, loglik] = enter_evidence(engine, evidence, varargin)% this is unchanged from bk_inf_engine.% ENTER_EVIDENCE Add the specified evidence to the network (bk)% [engine, loglik] = enter_evidence(engine, evidence, ...)%% evidence{i,t} = [] if if X(i,t) is hidden, and otherwise contains its observed value (scalar or column vector)%% The following optional arguments can be specified in the form of name/value pairs:% [default value in brackets]%% maximize - if 1, does max-product instead of sum-product [0]% filter -   if 1, do filtering, else smoothing [0]%% e.g., engine = enter_evidence(engine, ev, 'maximize', 1)maximize = 0;filter = 0;% parse optional paramsargs = varargin;nargs = length(args);if nargs > 0  for i=1:2:nargs    switch args{i},     case 'maximize', maximize = args{i+1};      case 'filter', filter = args{i+1};      otherwise,        error(['invalid argument name ' args{i}]);           end  endend[ss T] = size(evidence);engine.filter = filter;engine.maximize = maximize;engine.T = T;if maximize  error('BK does not yet support max propagation')  % because it calls enter_soft_evidence, not enter_evidenceendobserved_bitv = ~isemptycell(evidence);onodes = find(observed_bitv);bnet = bnet_from_engine(engine);pot_type = determine_pot_type(bnet, onodes); CPDpot = convert_dbn_CPDs_to_pots(bnet, evidence, pot_type);[engine.clpot, loglik] = enter_soft_evidence(engine, CPDpot, observed_bitv, pot_type, filter);