Mauch MIREX 2010

function CPD = tabular_decision_node(bnet, self, CPT)

% TABULAR_DECISION_NODE Represent a stochastic policy over a discrete decision/action node as a table

% CPD = tabular_decision_node(bnet, self, CPT)

%

% node is the number of a node in this equivalence class.

% CPT is an optional argument (see tabular_CPD for details); by default, it is the uniform policy.

if nargin==0

  % This occurs if we are trying to load an object from a file.

  CPD = init_fields;

  CPD = class(CPD, 'tabular_decision_node', discrete_CPD(1, []));

  return;

elseif isa(bnet, 'tabular_decision_node')

  % This might occur if we are copying an object.

  CPD = bnet;

  return;

end

CPD = init_fields;

ns = bnet.node_sizes;

fam = family(bnet.dag, self);

ps = parents(bnet.dag, self);

sz = ns(fam);

if nargin < 3

  CPT = mk_stochastic(myones(sz)); 

else

  CPT = myreshape(CPT, sz);

end

CPD.CPT = CPT;

CPD.sizes = sz; 

clamped = 1; % don't update using EM

CPD = class(CPD, 'tabular_decision_node', discrete_CPD(clamped, ns([ps self])));

%%%%%%%%%%%

function CPD = init_fields()

% This ensures we define the fields in the same order 

% no matter whether we load an object from a file,

% or create it from scratch. (Matlab requires this.)

CPD.CPT = [];

CPD.sizes = [];