Mauch MIREX 2010

function [mpe, prob] = calc_mpe_given_inf_engine(engine, evidence)

% CALC_MPE_GIVEN_ENGINE Computes the most probable explanation of the evidence

% [mpe, prob] = calc_mpe_given_inf_engine(engine, evidence)

%

% INPUT

% engine must support max-propagation

% evidence{i} is the obsevred value of node i, or [] if hidden

%

% OUTPUT

% mpe(i) is the most likely value of node i

% prob is the likelihood of the globally best assignment

%

% This currently only works when all nodes are discrete

[engine, ll] = enter_evidence(engine, evidence);

observed = ~isemptycell(evidence);

N = length(evidence);

mpe = zeros(1,N);

for i=1:N

  m = marginal_nodes(engine, i);

  % discrete observed nodes are all set to 1 inside the inference engine, so we must undo this

  if observed(i)

    mpe(i) = evidence{i};

  else

    mpe(i) = argmax(m.T);

  end

end

bnet = bnet_from_engine(engine);

ll = log_lik_complete(bnet, num2cell(mpe(:)));

prob = exp(ll);