public void TestBreakAtFirstTransition()
{
var viterbi = new ViterbiModel <Rain, Umbrella, Descriptor>();
var candidates = new List <Rain>();
candidates.Add(Rain.T);
candidates.Add(Rain.F);
var emissionLogProbabilities = new Dictionary <Rain, double>();
emissionLogProbabilities[Rain.T] = Math.Log(0.9);
emissionLogProbabilities[Rain.F] = Math.Log(0.2);
viterbi.Start(Umbrella.T, candidates, emissionLogProbabilities);
Assert.False(viterbi.IsBroken);
var transitionLogProbabilities = new Dictionary <Transition <Rain>, double>();
transitionLogProbabilities[new Transition <Rain>(Rain.T, Rain.T)] = Math.Log(0.0);
transitionLogProbabilities[new Transition <Rain>(Rain.T, Rain.F)] = Math.Log(0.0);
transitionLogProbabilities[new Transition <Rain>(Rain.F, Rain.T)] = Math.Log(0.0);
transitionLogProbabilities[new Transition <Rain>(Rain.F, Rain.F)] = Math.Log(0.0);
viterbi.NextStep(Umbrella.T, candidates, emissionLogProbabilities,
transitionLogProbabilities);
Assert.True(viterbi.IsBroken);
//assertEquals(Arrays.asList(Rain.T), states(viterbi.computeMostLikelySequence()));
}
/**
* Checks if the first candidate is returned if multiple candidates are equally likely.
*/
public void TestDeterministicCandidateOrder()
{
var candidates = new List <Rain>();
candidates.Add(Rain.T);
candidates.Add(Rain.F);
// Reverse usual order of emission and transition probabilities keys since their order
// should not matter.
var emissionLogProbabilitiesForUmbrella = new Dictionary <Rain, double>();
emissionLogProbabilitiesForUmbrella[Rain.F] = Math.Log(0.5);
emissionLogProbabilitiesForUmbrella[Rain.T] = Math.Log(0.5);
var emissionLogProbabilitiesForNoUmbrella = new Dictionary <Rain, double>();
emissionLogProbabilitiesForNoUmbrella[Rain.F] = Math.Log(0.5);
emissionLogProbabilitiesForNoUmbrella[Rain.T] = Math.Log(0.5);
var transitionLogProbabilities = new Dictionary <Transition <Rain>, double>();
transitionLogProbabilities[new Transition <Rain>(Rain.F, Rain.T)] = Math.Log(0.5);
transitionLogProbabilities[new Transition <Rain>(Rain.F, Rain.F)] = Math.Log(0.5);
transitionLogProbabilities[new Transition <Rain>(Rain.T, Rain.T)] = Math.Log(0.5);
transitionLogProbabilities[new Transition <Rain>(Rain.T, Rain.F)] = Math.Log(0.5);
var viterbi = new ViterbiModel <Rain, Umbrella, Descriptor>();
viterbi.Start(Umbrella.T, candidates,
emissionLogProbabilitiesForUmbrella);
viterbi.NextStep(Umbrella.T, candidates, emissionLogProbabilitiesForUmbrella,
transitionLogProbabilities);
viterbi.NextStep(Umbrella.F, candidates, emissionLogProbabilitiesForNoUmbrella,
transitionLogProbabilities);
viterbi.NextStep(Umbrella.T, candidates, emissionLogProbabilitiesForUmbrella,
transitionLogProbabilities);
var result = viterbi.ComputeMostLikelySequence();
// Check most likely sequence
Assert.Equal(4, result.Count);
Assert.Equal(Rain.T, result[0].State);
Assert.Equal(Rain.T, result[1].State);
Assert.Equal(Rain.T, result[2].State);
Assert.Equal(Rain.T, result[3].State);
}