Mauch MIREX 2010

function y = sample_node(CPD, pvals)

% SAMPLE_NODE Draw a random sample from P(Xi | x(pi_i), theta_i)  (discrete)

% y = sample_node(CPD, parent_evidence)

%

% parent_evidence{i} is the value of the i'th parent

if 0

n = length(pvals)+1;

dom = 1:n;

evidence = cell(1,n);

evidence(1:n-1) = pvals;

T = convert_to_table(CPD, dom, evidence);

y = sample_discrete(T);

end

CPT = CPD_to_CPT(CPD);

sz = mysize(CPT);

nparents = length(sz)-1;

switch nparents

 case 0, T = CPT;

 case 1, T = CPT(pvals{1}, :);

 case 2, T = CPT(pvals{1}, pvals{2}, :);

 case 3, T = CPT(pvals{1}, pvals{2}, pvals{3}, :);

 case 4, T = CPT(pvals{1}, pvals{2}, pvals{3}, pvals{4}, :);

 otherwise,

  pvals = cat(1, pvals{:});

  psz = sz(1:end-1);

  ssz = sz(end);

  i = subv2ind(psz, pvals(:)');

  T = reshape(CPT, [prod(psz) ssz]);

  T = T(i,:);

end

y = sample_discrete(T);