private double[] PredictNextValue(IGaussianMixtureModelState model, IPredictionRequest request, double[][] trainingSet)
{
var N = trainingSet.Length;
var K = trainingSet[0].Length;
var result = new double[K];
var yesterday = trainingSet[N - 1];
var yesterdayLikelihood = LogLikelihood.Calculate(new[] { yesterday }, model.Mixture.Coefficients, GetCovariances(model.Mixture.Components), GetMeans(model.Mixture.Components));
Debug.WriteLine("Yesterday Likelihood : " + new Vector(yesterday) + " : " + yesterdayLikelihood + " ");
var guessess = FindMostSimilarObservations(model, trainingSet, yesterdayLikelihood, request.Tolerance);
var bestGuessPlace = FindBestGuess(request, guessess);
var tomorrow = trainingSet[bestGuessPlace.PlaceInSequence + 1];
var mostSimilar = trainingSet[bestGuessPlace.PlaceInSequence];
for (var k = 0; k < K; k++)
{
if (bestGuessPlace.PlaceInSequence != trainingSet.Length)
{
result[k] = yesterday[k] + (tomorrow[k] - mostSimilar[k]);
}
}
Debug.WriteLine("Predicted : " + new Vector(result) + " : " + LogLikelihood.Calculate(new[] { result }, model.Mixture.Coefficients, GetCovariances(model.Mixture.Components), GetMeans(model.Mixture.Components)));
return(result);
}
private ObservationWithLikelihood <double[]> FindBestGuess(IPredictionRequest request, IList <ObservationWithLikelihood <double[]> > guessess)
{
var result = new ObservationWithLikelihood <double[]>()
{
Observation = new double[request.TrainingSet[0].Length]
};
var maxLogLikelihood = double.NegativeInfinity;
for (var i = 0; i < guessess.Count; i++)
{
if (maxLogLikelihood < guessess[i].LogLikelihood)
{
maxLogLikelihood = guessess[i].LogLikelihood;
result.LogLikelihood = guessess[i].LogLikelihood;
result.Observation = guessess[i].Observation;
result.PlaceInSequence = guessess[i].PlaceInSequence;
result.NumberOfGuesses = guessess.Count;
}
}
Debug.Write(result.PlaceInSequence + " : " + (new Vector(result.Observation)) + " " + result.NumberOfGuesses + " " + Environment.NewLine);
return(result);
}
public IPredictionResult Predict(IGaussianMixtureModelState model, IPredictionRequest request)
{
var trainingSet = (double[][])request.TrainingSet.Clone();
var predictions = new PredictionResult {
Predicted = new double[request.NumberOfDays][]
};
for (int i = 0; i < request.NumberOfDays; i++)
{
var prediction = PredictNextValue(model, request, trainingSet);
if (request.NumberOfDays > 1)
{
trainingSet = new double[request.TrainingSet.Length + i + 1][];
request.TrainingSet.CopyTo(trainingSet, 0);
for (var j = 0; j < i + 1; j++)
{
trainingSet[request.TrainingSet.Length + j] = request.TestSet[j];
}
}
predictions.Predicted[i] = prediction;
}
return(predictions);
}
/// <summary>
/// Viterbi based prediction algorithm. For each observation in test set we perform following action :
/// 1. Run Viterbi and find best state that generated last day observation
/// 2. Prediction for next day is weighted average of means of predicting state emissions
/// 3. Re-Train the model with new value added from training set
/// 4. Return to step 1
/// </summary>
/// <typeparam name="TDistribution"></typeparam>
/// <param name="model"></param>
/// <param name="request"></param>
/// <returns></returns>
public IPredictionResult Predict <TDistribution>(IHiddenMarkovModel <TDistribution> model, IPredictionRequest request) where TDistribution : IDistribution
{
NumberOfIterations = request.NumberOfTrainingIterations;
LikelihoodTolerance = request.TrainingLikelihoodTolerance;
var predictions = new PredictionResult {
Predicted = new double[request.NumberOfDays][]
};
var trainingSet = (double[][])request.TrainingSet.Clone();
for (int i = 0; i < request.NumberOfDays; i++)
{
var prediction = PredictNextValue(model, trainingSet);
if (request.NumberOfDays > 1)
{
trainingSet = new double[request.TrainingSet.Length + i + 1][];
request.TrainingSet.CopyTo(trainingSet, 0);
for (var j = 0; j < i + 1; j++)
{
trainingSet[request.TrainingSet.Length + j] = request.TestSet[j];
}
var iterations = NumberOfIterations;
((IMachineLearningMultivariateModel)model).Train(trainingSet, iterations, LikelihoodTolerance);
}
predictions.Predicted[i] = prediction;
}
return(predictions);
}
public IPredictionResult Predict <TDistribution>(IHiddenMarkovModel <TDistribution> model, IPredictionRequest request)
where TDistribution : IDistribution
{
var trainingSet = (double[][])request.TrainingSet.Clone();
var predictions = new PredictionResult {
Predicted = new double[request.NumberOfDays][]
};
for (int i = 0; i < request.NumberOfDays; i++)
{
var prediction = PredictNextValue(model, request, trainingSet);
if (request.NumberOfDays > 1)
{
trainingSet = new double[request.TrainingSet.Length + i + 1][];
request.TrainingSet.CopyTo(trainingSet, 0);
for (var j = 0; j < i + 1; j++)
{
trainingSet[request.TrainingSet.Length + j] = request.TestSet[j];
}
}
predictions.Predicted[i] = prediction;
}
return(predictions);
}
private double[] PredictNextValue <TDistribution>(IHiddenMarkovModel <TDistribution> model, IPredictionRequest request, double[][] trainingSet)
where TDistribution : IDistribution
{
var N = trainingSet.Length;
var K = trainingSet[0].Length;
var result = new double[K];
var yesterday = trainingSet[N - 1];
var forwardBackward = new ForwardBackward(model.Normalized);
var yesterdayLikelihood = forwardBackward.RunForward(Helper.Convert(new[] { yesterday }), model);
Debug.WriteLine("Yesterday Likelihood : " + new Vector(yesterday) + " : " + yesterdayLikelihood + " ");
var guessess = FindMostSimilarObservations(model, trainingSet, yesterdayLikelihood, request.Tolerance);
var bestGuessPlace = FindBestGuess(request, guessess);
var tomorrow = trainingSet[bestGuessPlace.PlaceInSequence + 1];
var mostSimilar = trainingSet[bestGuessPlace.PlaceInSequence];
for (var k = 0; k < K; k++)
{
if (bestGuessPlace.PlaceInSequence != trainingSet.Length)
{
result[k] = yesterday[k] + (tomorrow[k] - mostSimilar[k]);
}
}
Debug.WriteLine("Predicted (for day " + N + ") : " + new Vector(result) + " : " + forwardBackward.RunForward(Helper.Convert(result), model));
return(result);
}
public IPredictionResult Predict <TDistribution>(IHiddenMarkovModel <TDistribution> model, IPredictionRequest request) where TDistribution : IDistribution
{
var selectionMethod = new TournamentSelection(TournamentSize);
var crossoverAlgorithm = new Crossover(CrossoverProbability);
var mutationAlgorithm = new Mutator(MutationProbability);
var evaluator = new HmmEvaluator <TDistribution>(model, new ForwardBackward(true));
var parameters = new GeneticSolverParameters
{
CrossOverProbability = CrossoverProbability,
MutationProbability = MutationProbability,
NumberOfGenerations = NumberOfGenerations,
PopulationSize = request.NumberOfDays * 10,
TournamentSize = TournamentSize
};
var predictions = new PredictionResult {
Predicted = new double[request.NumberOfDays][]
};
var solver = new GeneticSolver(parameters, mutationAlgorithm, crossoverAlgorithm, evaluator, selectionMethod);
var populationInitializer = new FromTimeSeriesRandomInitializer(request.TrainingSet);
var population = populationInitializer.Initialize <decimal>(parameters.PopulationSize, request.NumberOfDays, MutationProbability);
for (int i = 0; i < population.Count; i++)
{
var chromosome = population[i];
population[i].FintnessValue = evaluator.Evaluate(chromosome);
}
var result = solver.Solve(population);
// Get best fitted chromosome
var maximumFitness = result[0].FintnessValue;
var solution = result[0];
foreach (var chromosome in result)
{
if (maximumFitness <= chromosome.FintnessValue)
{
solution = chromosome;
maximumFitness = chromosome.FintnessValue;
}
}
// Convert it to array
for (int i = 0; i < solution.Representation.Length; i++)
{
predictions.Predicted[i] = Array.ConvertAll(solution.Representation[i].Representation, x => (double)Convert.ChangeType(x, typeof(double)));
}
return(predictions);
}
public IPredictionResult Predict <TDistribution>(IHiddenMarkovModel <TDistribution> model, IPredictionRequest request) where TDistribution : IDistribution
{
if (!request.ValidateAlgorithmSpecificParameters())
{
return(null);
}
var n = Convert.ToInt32(request.AlgorithmSpecificParameters["NumberOfSamplePoints"]);
var k = Convert.ToInt32(request.AlgorithmSpecificParameters["NumberOfWinningPoints"]);
//var ratios = GetMaximumChangeRatios(request.TrainingSet);
//var candidates = CreateStartingPool(request.TestSet[0], n, ratios);
/* do
* {
* //var winningCandidate = CalculateWinningCandidates(k, candidates, model);
* //candidates = CreateCandidatePoolFromArray(winningCandidate, n, ratios);
* } while (Continue(request, candidates));*/
var result = new PredictionResult()
{
Predicted = new double[1][]
};
//result.Predicted[0] = GetBestProbabilityCandidate(candidates);
return(result);
}
