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java.lang.Object  +com.cra.bnet.engine.DecisionAnalysisTools
Decision analysis utility class.
Method Summary  
static Map 
getMutualInformation(BayesianNetwork network,
DiscreteNode queryNode)
Returns an unmodifiable map containing the mutual information between the specified query variable and every variable in the specified Bayesian network (including the query variable itself). 
static Map 
getMutualInformation(BayesianNetwork network,
DiscreteNode queryNode,
double threshold)
Returns an unmodifiable map containing the mutual information between the specified query variable and every variable in the specified Bayesian network (including the query variable itself). 
Methods inherited from class java.lang.Object 
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait 
Method Detail 
public static Map getMutualInformation(BayesianNetwork network, DiscreteNode queryNode)
getMutualInformation(network, queryVariableId, 0.0);
network
 Bayesian network.queryNode
 query node.
public static Map getMutualInformation(BayesianNetwork network, DiscreteNode queryNode, double threshold)
Values less than or equal to the specified threshold are not included in the returned map.
Mutual information between a query variable Q and a findings variable F is described in Pearl pg321323, and is defined as:
MI(Q,F) = SUMq SUMf P(q,fe) * log(P(q,fe) / (P(qe) * P(fe))) MI(Q,Q) = SUMq P(qe) * log(P(qe))
Mutual information gives the expected reduction in entropy of the query variable Q due to a finding on the findings variable F. Thus, mutual information gives a measure of how sensitive variable Q is to evidence on variable F. Note also that mutual information is symmetric between nodes, so MI(Q,F) = MI(F,Q).
The log function in the above equations has base 2; this stems from the entropy equation in information theory where log2(N) gives the number of bits required to represent N different messages.
If the specified Bayesian network is disconnected, this method will return an empty map.
network
 Bayesian network.queryNode
 query node.threshold
 the threshold for filtering values.


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