Пример #1
0
        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()));
        }
Пример #2
0
        public void TestEmptyInitialMessage()
        {
            var viterbi = new ViterbiModel <Rain, Umbrella, Descriptor>();

            viterbi.Start(Umbrella.T, new List <Rain>(), new Dictionary <Rain, Double>());
            Assert.True(viterbi.IsBroken);
            //assertEquals(Arrays.asList(), viterbi.computeMostLikelySequence());
        }
Пример #3
0
        public void TestBreakAtInitialMessage()
        {
            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(0.0);
            emissionLogProbabilities[Rain.F] = Math.Log(0.0);
            viterbi.Start(Umbrella.T, candidates, emissionLogProbabilities);
            Assert.True(viterbi.IsBroken);
            //Assert.Equal(Arrays.asList(), viterbi.computeMostLikelySequence());
        }
Пример #4
0
        /**
         * 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);
        }