/// <summary>
/// Define a relationship.
/// </summary>
/// <param name="line">The relationship to define.</param>
public void DefineRelationship(String line)
{
var parse = new ParseProbability(this);
ParsedProbability parsedProbability = parse.Parse(line);
parsedProbability.DefineRelationships(this);
}
/// <summary>
/// Define the probability for an event.
/// </summary>
/// <param name="line">The event.</param>
/// <param name="probability">The probability.</param>
public void DefineProbability(String line, double probability)
{
var parse = new ParseProbability(this);
ParsedProbability parsedProbability = parse.Parse(line);
parsedProbability.DefineTruthTable(this, probability);
}
/// <summary>
/// Define a classification structure of the form P(A|B) = P(C)
/// </summary>
/// <param name="line">The structure.</param>
public void DefineClassificationStructure(String line)
{
IList <ParsedProbability> list = ParseProbability.ParseProbabilityList(this, line);
if (list.Count > 1)
{
throw new BayesianError("Must only define a single probability, not a chain.");
}
if (list.Count == 0)
{
throw new BayesianError("Must define at least one probability.");
}
// first define everything to be hidden
foreach (BayesianEvent e in _events)
{
Query.DefineEventType(e, EventType.Hidden);
}
// define the base event
ParsedProbability prob = list[0];
if (prob.BaseEvents.Count == 0)
{
return;
}
BayesianEvent be = GetEvent(prob.ChildEvent.Label);
_classificationTarget = _events.IndexOf(be);
Query.DefineEventType(be, EventType.Outcome);
// define the given events
foreach (ParsedEvent parsedGiven in prob.GivenEvents)
{
BayesianEvent given = GetEvent(parsedGiven.Label);
Query.DefineEventType(given, EventType.Evidence);
}
Query.LocateEventTypes();
// set the values
foreach (ParsedEvent parsedGiven in prob.GivenEvents)
{
BayesianEvent e = GetEvent(parsedGiven.Label);
Query.SetEventValue(e, ParseInt(parsedGiven.Value));
}
Query.SetEventValue(be, ParseInt(prob.BaseEvents[0].Value));
}
/// <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);
}
