public void TestSampling1()
{
BayesianNetwork network = new BayesianNetwork();
BayesianEvent a = network.CreateEvent("a");
BayesianEvent b = network.CreateEvent("b");
network.CreateDependency(a, b);
network.FinalizeStructure();
a.Table.AddLine(0.5, true); // P(A) = 0.5
b.Table.AddLine(0.2, true, true); // p(b|a) = 0.2
b.Table.AddLine(0.8, true, false);// p(b|~a) = 0.8
network.Validate();
SamplingQuery query = new SamplingQuery(network);
query.DefineEventType(a, EventType.Evidence);
query.DefineEventType(b, EventType.Outcome);
query.SetEventValue(b, true);
query.SetEventValue(a, true);
query.Execute();
TestPercent(query.Probability, 20);
}
/// <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;
}
public void TestSampling2()
{
BayesianNetwork network = new BayesianNetwork();
BayesianEvent a = network.CreateEvent("a");
BayesianEvent x1 = network.CreateEvent("x1");
BayesianEvent x2 = network.CreateEvent("x2");
BayesianEvent x3 = network.CreateEvent("x3");
network.CreateDependency(a, x1, x2, x3);
network.FinalizeStructure();
a.Table.AddLine(0.5, true); // P(A) = 0.5
x1.Table.AddLine(0.2, true, true); // p(x1|a) = 0.2
x1.Table.AddLine(0.6, true, false);// p(x1|~a) = 0.6
x2.Table.AddLine(0.2, true, true); // p(x2|a) = 0.2
x2.Table.AddLine(0.6, true, false);// p(x2|~a) = 0.6
x3.Table.AddLine(0.2, true, true); // p(x3|a) = 0.2
x3.Table.AddLine(0.6, true, false);// p(x3|~a) = 0.6
network.Validate();
SamplingQuery query = new SamplingQuery(network);
query.DefineEventType(x1, EventType.Evidence);
query.DefineEventType(x2, EventType.Evidence);
query.DefineEventType(x3, EventType.Evidence);
query.DefineEventType(a, EventType.Outcome);
query.SetEventValue(a, true);
query.SetEventValue(x1, true);
query.SetEventValue(x2, true);
query.SetEventValue(x3, false);
query.Execute();
TestPercent(query.Probability, 18);
}