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<< Click to Display Table of Contents >> Navigation: Tutorials > Tutorial 5: Inference in an Influence Diagram > Tutorial5.cs |
using System;
using Smile;
// Tutorial5 loads the XDSL file created by Tutorial4,
// then performs the series of inference calls,
// changing evidence each time.
namespace SmileNetTutorial
{
class Tutorial5
{
public static void Run()
{
Console.WriteLine("Starting Tutorial5...");
Network net = new Network();
net.ReadFile("tutorial4.xdsl");
Console.WriteLine("No evidence set.");
net.UpdateBeliefs();
PrintFinancialGain(net);
Console.WriteLine("Setting Forecast=Good.");
ChangeEvidenceAndUpdate(net, "Forecast", "Good");
Console.WriteLine("Adding Economy=Up");
ChangeEvidenceAndUpdate(net, "Economy", "Up");
Console.WriteLine("Tutorial5 complete.");
}
static void ChangeEvidenceAndUpdate(
Network net, String nodeId, String outcomeId)
{
if (outcomeId != null)
{
net.SetEvidence(nodeId, outcomeId);
}
else
{
net.ClearEvidence(nodeId);
}
net.UpdateBeliefs();
PrintFinancialGain(net);
}
static void PrintFinancialGain(Network net)
{
double[] expectedUtility = net.GetNodeValue("Gain");
int[] utilParents = net.GetValueIndexingParents("Gain");
printGainMatrix(net, expectedUtility, utilParents);
}
static void printGainMatrix(Network net, double[] mtx, int[] parents)
{
int dimCount = 1 + parents.Length;
int[] dimSizes = new int[dimCount];
for (int i = 0; i < dimCount - 1; i++)
{
dimSizes[i] = net.GetOutcomeCount(parents[i]);
}
dimSizes[dimSizes.Length - 1] = 1;
int[] coords = new int[dimCount];
for (int elemIdx = 0; elemIdx < mtx.Length; elemIdx++)
{
IndexToCoords(elemIdx, dimSizes, coords);
Console.Write(" Utility(");
if (dimCount > 1)
{
for (int pIdx = 0; pIdx < parents.Length; pIdx++)
{
if (pIdx > 0) Console.Write(",");
int parentHandle = parents[pIdx];
Console.Write("{0}={1}",
net.GetNodeId(parentHandle),
net.GetOutcomeId(parentHandle, coords[pIdx]));
}
}
Console.Write(")={0}\n", mtx[elemIdx]);
}
Console.WriteLine();
}
static void IndexToCoords(int index, int[] dimSizes, int[] coords)
{
int prod = 1;
for (int i = dimSizes.Length - 1; i >= 0; i--)
{
coords[i] = (index / prod) % dimSizes[i];
prod *= dimSizes[i];
}
}
}
}