/// <summary>
/// Perform a query.
/// </summary>
/// <param name="line">The query.</param>
/// <returns>The probability.</returns>
public double PerformQuery(String line)
{
if (Query == null)
{
throw new BayesianError("This Bayesian network does not have a query to define.");
}
var parse = new ParseProbability(this);
ParsedProbability parsedProbability = parse.Parse(line);
// create a temp query
IBayesianQuery q = Query.Clone();
// first, mark all events as hidden
q.Reset();
// deal with evidence (input)
foreach (ParsedEvent parsedEvent in parsedProbability.GivenEvents)
{
BayesianEvent e = RequireEvent(parsedEvent.Label);
q.DefineEventType(e, EventType.Evidence);
q.SetEventValue(e, parsedEvent.ResolveValue(e));
}
// deal with outcome (output)
foreach (ParsedEvent parsedEvent in parsedProbability.BaseEvents)
{
BayesianEvent e = RequireEvent(parsedEvent.Label);
q.DefineEventType(e, EventType.Outcome);
q.SetEventValue(e, parsedEvent.ResolveValue(e));
}
q.LocateEventTypes();
q.Execute();
return(q.Probability);
}
/// <summary>
/// Construct a Bayesian network.
/// </summary>
public BayesianNetwork()
{
this.Query = new EnumerationQuery(this);
}
/// <inheritdoc/>
public Object Read(Stream istream)
{
BayesianNetwork result = new BayesianNetwork();
EncogReadHelper input = new EncogReadHelper(istream);
EncogFileSection section;
String queryType = "";
String queryStr = "";
String contentsStr = "";
while ((section = input.ReadNextSection()) != null)
{
if (section.SectionName.Equals("BAYES-NETWORK") &&
section.SubSectionName.Equals("BAYES-PARAM"))
{
IDictionary <String, String> p = section.ParseParams();
queryType = p["queryType"];
queryStr = p["query"];
contentsStr = p["contents"];
}
if (section.SectionName.Equals("BAYES-NETWORK") &&
section.SubSectionName.Equals("BAYES-TABLE"))
{
result.Contents = contentsStr;
// first, define relationships (1st pass)
foreach (String line in section.Lines)
{
result.DefineRelationship(line);
}
result.FinalizeStructure();
// now define the probabilities (2nd pass)
foreach (String line in section.Lines)
{
result.DefineProbability(line);
}
}
if (section.SectionName.Equals("BAYES-NETWORK") &&
section.SubSectionName.Equals("BAYES-PROPERTIES"))
{
IDictionary <String, String> paras = section.ParseParams();
EngineArray.PutAll(paras, result.Properties);
}
}
// define query, if it exists
if (queryType.Length > 0)
{
IBayesianQuery query = null;
if (queryType.Equals("EnumerationQuery"))
{
query = new EnumerationQuery(result);
}
else
{
query = new SamplingQuery(result);
}
if (query != null && queryStr.Length > 0)
{
result.Query = query;
result.DefineClassificationStructure(queryStr);
}
}
return(result);
}
