Mauch MIREX 2010

function sample = sample_bnet(bnet, varargin)

% SAMPLE_BNET Generate a random sample from a Bayes net.

% SAMPLE = SAMPLE_BNET(BNET, ...)

%

% sample{i} contains the value of the i'th node.

% i.e., the result is an Nx1 cell array.

% Nodes are sampled in the order given by bnet.order.

%

% Optional arguments:

%

% evidence - initial evidence; if evidence{i} is non-empty, node i won't be sampled.

% set defauly params

n = length(bnet.dag);

sample = cell(n,1);

% get optional params

args = varargin;

nargs = length(args);

for i=1:2:nargs

  switch args{i},

   case 'evidence',    sample = args{i+1}(:);

   otherwise, error(['unrecognized argument ' args{i}])

  end

end

for j=bnet.order(:)'

  if isempty(sample{j})

    %ps = parents(bnet.dag, j);

    ps = bnet.parents{j};

    e = bnet.equiv_class(j);

    sample{j} = sample_node(bnet.CPD{e}, sample(ps));

  end

end