public static void TestSVM(double[][] inputs, int[] outputs)
{
var crossValidation = new CrossValidation(inputs.Length, 10);
crossValidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
var trainingInputs = inputs.Submatrix(indicesTrain);
var trainingOutputs = outputs.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = inputs.Submatrix(indicesValidation);
var validationOutputs = outputs.Submatrix(indicesValidation);
var sw1 = Stopwatch.StartNew();
var svm = new SVM();
var trainingError = svm.TrainSVM(new RationalQuadratic(1), 3, trainingInputs, trainingOutputs);
sw1.Stop();
Console.WriteLine("Training for: " + sw1.ElapsedMilliseconds + "ms with errors: " + trainingError);
var validationError = svm.GetSMO().ComputeError(validationInputs, validationOutputs);
// Return a new information structure containing the model and the errors achieved.
return(new CrossValidationValues(svm, trainingError, validationError));
};
// Compute the cross-validation
var result = crossValidation.Compute();
// Finally, access the measured performance.
var trainingErrors = result.Training.Mean;
var validationErrors = result.Validation.Mean;
Console.WriteLine("Finished with " + trainingErrors + " training errors and " + validationErrors + " validation errors");
}
public CrossValidationResult <object> Validate(IClassifier classifier, TrainingData trainingData, int folds = 10)
{
var crossValidation = new CrossValidation(size: trainingData.Inputs.Length, folds: folds);
crossValidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
var trainingInputs = trainingData.Inputs.Get(indicesTrain);
var trainingOutputs = trainingData.Outputs.Get(indicesTrain);
var validationInputs = trainingData.Inputs.Get(indicesValidation);
var validationOutputs = trainingData.Outputs.Get(indicesValidation);
var foldClassifier = classifier.CreateInstance(trainingData.FeatureDefaultsValueTypes, trainingData.FeatureGranularities);
foldClassifier.Train(trainingInputs, trainingOutputs);
var trainingPredicted = foldClassifier.Decide(trainingInputs);
var validationPredicted = foldClassifier.Decide(validationInputs);
double trainingError = new ZeroOneLoss(trainingOutputs).Loss(trainingPredicted);
double validationError = new ZeroOneLoss(validationOutputs).Loss(validationPredicted);
var confusionMatrix = new ConfusionMatrix(validationPredicted, validationOutputs, positiveValue: 1, negativeValue: 0);
Console.WriteLine($"{k}\t{trainingError}\t{validationError}\t{confusionMatrix.Accuracy}\t{confusionMatrix.TruePositives}\t{confusionMatrix.TrueNegatives}\t{confusionMatrix.FalsePositives}\t{confusionMatrix.FalseNegatives}\t{confusionMatrix.FalsePositiveRate}");
return(new CrossValidationValues(foldClassifier, trainingError, validationError));
};
var result = crossValidation.Compute();
return(result);
}
public static void TestKNN(double[][] inputs, int[] outputs, int kValue)
{
var crossValidation = new CrossValidation(inputs[0].Length, 10);
crossValidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
var trainingInputs = inputs.Submatrix(indicesTrain);
var trainingOutputs = outputs.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = inputs.Submatrix(indicesValidation);
var validationOutputs = outputs.Submatrix(indicesValidation);
var sw = Stopwatch.StartNew();
var knn = new KNN();
knn.TrainKNN(trainingInputs, trainingOutputs, kValue);
sw.Stop();
//Console.WriteLine("Training for: " + sw.ElapsedMilliseconds + "ms");
var error = knn.ComputeError(validationInputs, validationOutputs);
return(new CrossValidationValues(knn, 0, error));
};
// Compute the cross-validation
var result = crossValidation.Compute();
// Finally, access the measured performance.
var trainingErrors = result.Training.Mean;
var validationErrors = result.Validation.Mean;
Console.WriteLine("Finished with " + trainingErrors + " training errors and " + validationErrors + " validation errors");
}
public void NotEnoughSamplesTest2()
{
Accord.Math.Tools.SetupGenerator(0);
int[] labels = Matrix.Vector(10, 1).Concatenate(Matrix.Vector(30, 0));
Vector.Shuffle(labels);
var crossvalidation = new CrossValidation <MulticlassSupportVectorMachine>(labels, 2, folds: 10)
{
RunInParallel = false,
Fitting = (int index, int[] indicesTrain, int[] indicesValidation) =>
{
var labelsValidation = labels.Submatrix(indicesValidation);
int countValidation = labelsValidation.Count(x => x == 1);
Assert.AreEqual(1, countValidation);
var labelsTraining = labels.Submatrix(indicesTrain);
int countTraining = labelsTraining.Count(x => x == 1);
Assert.AreEqual(9, countTraining);
return(new CrossValidationValues <MulticlassSupportVectorMachine>(null, 0, 0));
}
};
crossvalidation.Compute();
}
public void FittingTest()
{
int[] folds = CrossValidation.Splittings(100, 10);
int[] samples = Matrix.Indices(0, 100);
CrossValidation val = new CrossValidation(folds, 10);
val.RunInParallel = false;
int current = 0;
val.Fitting = (k, trainingSamples, validationSamples) =>
{
Assert.AreEqual(current, k);
Assert.AreEqual(90, trainingSamples.Length);
Assert.AreEqual(10, validationSamples.Length);
int[] trainingSet = samples.Submatrix(trainingSamples);
int[] validationSet = samples.Submatrix(validationSamples);
for (int i = 0; i < trainingSet.Length; i++)
{
Assert.AreEqual(samples[trainingSamples[i]], trainingSet[i]);
}
for (int i = 0; i < validationSet.Length; i++)
{
Assert.AreEqual(samples[validationSamples[i]], validationSet[i]);
}
current++;
return(new CrossValidationValues(k, 2 * k));
};
var result = val.Compute();
Assert.AreEqual(10, current);
Assert.AreEqual(4.5, result.Training.Mean);
Assert.AreEqual(9.0, result.Validation.Mean);
Assert.AreEqual(
2 * result.Training.StandardDeviation,
result.Validation.StandardDeviation);
Assert.AreEqual(val.Folds.Length, result.Training.Sizes.Length);
Assert.AreEqual(val.Folds.Length, result.Validation.Sizes.Length);
for (int i = 0; i < result.Training.Sizes.Length; i++)
{
Assert.AreEqual(90, result.Training.Sizes[i]);
}
for (int i = 0; i < result.Validation.Sizes.Length; i++)
{
Assert.AreEqual(10, result.Validation.Sizes[i]);
}
}
public override Task <List <GeneralConfusionMatrix> > ComputeFoldedConfusionMatrixAsync(ClassificationModel classificationModel, int folds)
{
return(Task.Factory.StartNew(() =>
{
int numFeatures = classificationModel.FeatureVectors.Count;
DecisionVariable[] decisionVariables = Enumerable.ToArray(classificationModel.Bands.Select(b => DecisionVariable.Continuous(b.ToString())));
double[][] input = new double[numFeatures][];
int[] responses = new int[numFeatures];
for (int featureIndex = 0; featureIndex < classificationModel.FeatureVectors.Count; ++featureIndex)
{
var featureVector = classificationModel.FeatureVectors[featureIndex];
input[featureIndex] = Array.ConvertAll(featureVector.FeatureVector.BandIntensities, s => (double)s / ushort.MaxValue);
responses[featureIndex] = featureVector.FeatureClass;
}
List <GeneralConfusionMatrix> confusionMatrices = new List <GeneralConfusionMatrix>();
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation(input.Length, folds);
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// Lets now grab the training data:
var trainingInputs = input.Get(indicesTrain);
var trainingOutputs = responses.Get(indicesTrain);
// And now the validation data:
var validationInputs = input.Get(indicesValidation);
var validationOutputs = responses.Get(indicesValidation);
var tree = new DecisionTree(decisionVariables, Enum.GetValues(typeof(LandcoverTypeViewModel)).Length);
C45Learning id3Learning = new C45Learning(tree);
id3Learning.Learn(trainingInputs, trainingOutputs);
var predictedTraining = tree.Decide(trainingInputs);
var predictedValidation = tree.Decide(validationInputs);
double trainingError = new ZeroOneLoss(trainingOutputs).Loss(predictedTraining);
double validationError = new ZeroOneLoss(validationOutputs).Loss(predictedValidation);
GeneralConfusionMatrix confusionMatrix = new GeneralConfusionMatrix(Enum.GetValues(typeof(LandcoverTypeViewModel)).Length - 1, validationOutputs, predictedValidation);
confusionMatrices.Add(confusionMatrix);
// Return a new information structure containing the model and the errors achieved.
return new CrossValidationValues(trainingError, validationError);
};
var result = crossvalidation.Compute();
return confusionMatrices;
}));
}
public void NotEnoughSamplesTest1()
{
Accord.Math.Random.Generator.Seed = 0;
int[] labels = Matrix.Vector(10, 1).Concatenate(Matrix.Vector(30, 0));
Vector.Shuffle(labels);
var crossvalidation = new CrossValidation <MulticlassSupportVectorMachine>(size: 40, folds: 10)
{
RunInParallel = false,
Fitting = (int index, int[] indicesTrain, int[] indicesValidation) =>
{
var labelsValidation = labels.Submatrix(indicesValidation);
int countValidation = labelsValidation.Count(x => x == 1);
Assert.AreEqual(2, countValidation);
var labelsTraining = labels.Submatrix(indicesTrain);
int countTraining = labelsTraining.Count(x => x == 1);
Assert.AreEqual(9 * 2, countTraining);
return(new CrossValidationValues <MulticlassSupportVectorMachine>(null, 0, 0));
}
};
bool thrown = false;
try { crossvalidation.Compute(); }
catch (Exception) { thrown = true; }
Assert.IsTrue(thrown);
crossvalidation = new CrossValidation <MulticlassSupportVectorMachine>(labels, 2, folds: 10)
{
RunInParallel = false,
Fitting = (int index, int[] indicesTrain, int[] indicesValidation) =>
{
var labelsValidation = labels.Submatrix(indicesValidation);
int countValidation = labelsValidation.Count(x => x == 1);
Assert.AreEqual(1, countValidation);
var labelsTraining = labels.Submatrix(indicesTrain);
int countTraining = labelsTraining.Count(x => x == 1);
Assert.AreEqual(9, countTraining);
return(new CrossValidationValues <MulticlassSupportVectorMachine>(null, 0, 0));
}
};
crossvalidation.Compute();
}
public override Task <List <GeneralConfusionMatrix> > ComputeFoldedConfusionMatrixAsync(ClassificationModel classificationModel, int folds)
{
return(Task.Factory.StartNew(() =>
{
int numFeatures = classificationModel.FeatureVectors.Count;
double[][] input = new double[numFeatures][];
int[] responses = new int[numFeatures];
for (int featureIndex = 0; featureIndex < classificationModel.FeatureVectors.Count; ++featureIndex)
{
var featureVector = classificationModel.FeatureVectors[featureIndex];
input[featureIndex] = Array.ConvertAll(featureVector.FeatureVector.BandIntensities, s => (double)s / ushort.MaxValue);
responses[featureIndex] = featureVector.FeatureClass;
}
List <GeneralConfusionMatrix> confusionMatrices = new List <GeneralConfusionMatrix>();
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation(input.Length, folds);
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// Lets now grab the training data:
var trainingInputs = input.Get(indicesTrain);
var trainingOutputs = responses.Get(indicesTrain);
// And now the validation data:
var validationInputs = input.Get(indicesValidation);
var validationOutputs = responses.Get(indicesValidation);
int[] predictedTraining;
int[] predictedValidation;
TrainAndPredict(Complexity, Gamma, Degree, trainingInputs, trainingOutputs, validationInputs, out predictedTraining, out predictedValidation);
double trainingError = new ZeroOneLoss(trainingOutputs).Loss(predictedTraining);
double validationError = new ZeroOneLoss(validationOutputs).Loss(predictedValidation);
GeneralConfusionMatrix confusionMatrix = new GeneralConfusionMatrix(classificationModel.LandCoverTypes.Count, validationOutputs, predictedValidation);
confusionMatrices.Add(confusionMatrix);
// Return a new information structure containing the model and the errors achieved.
return new CrossValidationValues(trainingError, validationError);
};
crossvalidation.Compute();
return confusionMatrices;
}));
}
private void button1_Click(object sender, EventArgs e)
{
// Creates a matrix from the source data table
double[,] sourceMatrix = (dgvLearningSource.DataSource as DataTable).ToMatrix(out sourceColumns);
// Get only the input vector values
var inputs = sourceMatrix.Submatrix(0, sourceMatrix.GetLength(0) - 1, 0, 1).ToArray();
// Get only the label outputs
var outputs = new int[sourceMatrix.GetLength(0)];
for (int i = 0; i < outputs.Length; i++)
{
outputs[i] = (int)sourceMatrix[i, 2];
}
var cv = new CrossValidation <KernelSupportVectorMachine>(inputs.Length, 10);
cv.Fitting = (int k, int[] training, int[] testing) =>
{
var trainingInputs = inputs.Submatrix(training);
var trainingOutputs = outputs.Submatrix(training);
var testingInputs = inputs.Submatrix(testing);
var testingOutputs = outputs.Submatrix(testing);
// Create the specified Kernel
IKernel kernel = getKernel();
// Creates the Support Vector Machine using the selected kernel
var svm = new KernelSupportVectorMachine(kernel, 2);
// Creates a new instance of the SMO Learning Algortihm
var smo = new SequentialMinimalOptimization(svm, trainingInputs, trainingOutputs);
// Set learning parameters
smo.Complexity = (double)numC.Value;
smo.Tolerance = (double)numT.Value;
// Run
double trainingError = smo.Run();
double validationError = smo.ComputeError(testingInputs, testingOutputs);
return(new CrossValidationValues <KernelSupportVectorMachine>(svm, trainingError, validationError));
};
var result = cv.Compute();
}
public CrossValidationResult <RandomForest> GetCrossValidationResultsOfRandomForestModel(AppIdentAcordSource appIdentAcordSource, GridSearchParameterCollection bestParameters, int folds = 10)
{
var samples = appIdentAcordSource.Samples;
var labels = appIdentAcordSource.LabelsAsIntegers;
var decisionVariables = appIdentAcordSource.DecisionVariables;
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation <RandomForest>(samples.Length, folds)
{
Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// The fitting function is passing the indices of the original set which
// should be considered training data and the indices of the original set
// which should be considered validation data.
Console.WriteLine($"{DateTime.Now} RandomForest cross validation.");
// Lets now grab the training data:
var trainingInputs = samples.Get(indicesTrain);
var trainingOutputs = labels.Get(indicesTrain);
// And now the validation data:
var validationInputs = samples.Get(indicesValidation);
var validationOutputs = labels.Get(indicesValidation);
// create random forest model with the best parameters from grid search results
var rfcModel = CreateRandomForestModel(decisionVariables, bestParameters, trainingInputs, trainingOutputs);
// compute the training error rate with ZeroOneLoss function
var trainingError = new ZeroOneLoss(trainingOutputs).Loss(rfcModel.Decide(trainingInputs));
// Now we can compute the validation error on the validation data:
var validationError = new ZeroOneLoss(validationOutputs).Loss(rfcModel.Decide(validationInputs));
// Return a new information structure containing the model and the errors achieved.
var tag = new ValidationDataSource(validationInputs, validationOutputs);
return(new CrossValidationValues <RandomForest>(rfcModel, trainingError, validationError)
{
Tag = tag
});
}
};
// Compute the cross-validation
return(crossvalidation.Compute());
}
public void NotEnoughSamplesTest2()
{
Accord.Math.Tools.SetupGenerator(0);
int[] labels = Matrix.Vector(10, 1).Concatenate(Matrix.Vector(30, 0));
Accord.Statistics.Tools.Shuffle(labels);
var crossvalidation = new CrossValidation<MulticlassSupportVectorMachine>(labels, 2, folds: 10)
{
RunInParallel = false,
Fitting = (int index, int[] indicesTrain, int[] indicesValidation) =>
{
var labelsValidation = labels.Submatrix(indicesValidation);
int countValidation = labelsValidation.Count(x => x == 1);
Assert.AreEqual(1, countValidation);
var labelsTraining = labels.Submatrix(indicesTrain);
int countTraining = labelsTraining.Count(x => x == 1);
Assert.AreEqual(9, countTraining);
return new CrossValidationValues<MulticlassSupportVectorMachine>(null, 0, 0);
}
};
crossvalidation.Compute();
}
private int OptimizeK()
{
Tuple <KNearestNeighbors, double> bestModel = null;
for (int k = 50; k <= 200; k++)
{
var crossvalidation = new CrossValidation <KNearestNeighbors>(_input.Length, 5);
crossvalidation.Fitting = delegate(int fold, int[] indicesTrain, int[] indicesValidation)
{
var trainingInputs = _input.Submatrix(indicesTrain);
var trainingOutputs = _output.Submatrix(indicesTrain);
var validationInputs = _input.Submatrix(indicesValidation);
var validationOutputs = _output.Submatrix(indicesValidation);
var predictor = new KNearestNeighbors(k, _classes, trainingInputs, trainingOutputs);
// Create a training algorithm and learn the training data
var trainingError = 0.0;
for (int i = 0; i < trainingInputs.Length; i++)
{
int[] nearest;
predictor.GetNearestNeighbors(trainingInputs[i], out nearest);
var prediction = InverseDistanceWeightedAverage(nearest);
if (prediction > 0 && trainingOutputs[i] > 0 ||
prediction < 0 && trainingOutputs[i] < 0 ||
prediction.Equals(trainingOutputs[i]))
{
continue;
}
trainingError++;
}
double validationError = 0.0;
for (int i = 0; i < validationInputs.Length; i++)
{
int[] nearest;
predictor.GetNearestNeighbors(validationInputs[i], out nearest);
var prediction = InverseDistanceWeightedAverage(nearest);
if (prediction > 0 && validationOutputs[i] > 0 ||
prediction < 0 && validationOutputs[i] < 0 ||
prediction.Equals(validationOutputs[i]))
{
continue;
}
validationError++;
}
trainingError /= trainingInputs.Length;
validationError /= validationInputs.Length;
return(new CrossValidationValues <KNearestNeighbors>(predictor, trainingError, validationError));
};
var result = crossvalidation.Compute();
//var minError = result.Models.Select(y => y.ValidationValue).Min();
var minError = result.Models.Select(y => Math.Sqrt(Math.Pow(y.TrainingValue + y.ValidationValue, 2.0))).Min();
if (bestModel == null || minError < bestModel.Item2)
{
var bestFit = result.Models.FirstOrDefault(x => minError.Equals(x.ValidationValue))?.Model;
bestModel = bestFit == null ? bestModel : new Tuple <KNearestNeighbors, double>(bestFit, minError);
}
}
return(bestModel?.Item1.K ?? 80);
}
public void CrossvalidationConstructorTest2()
{
Accord.Math.Tools.SetupGenerator(0);
// This is a sample code on how to use Cross-Validation
// to assess the performance of Hidden Markov Models.
// Declare some testing data
int[][] inputs = new int[][]
{
new int[] { 0, 1, 1, 0 }, // Class 0
new int[] { 0, 0, 1, 0 }, // Class 0
new int[] { 0, 1, 1, 1, 0 }, // Class 0
new int[] { 0, 1, 1, 1, 0 }, // Class 0
new int[] { 0, 1, 1, 0 }, // Class 0
new int[] { 0, 1, 1, 1, 0 }, // Class 0
new int[] { 0, 1, 1, 1, 0 }, // Class 0
new int[] { 0, 1, 0, 1, 0 }, // Class 0
new int[] { 0, 1, 0 }, // Class 0
new int[] { 0, 1, 1, 0 }, // Class 0
new int[] { 1, 0, 0, 1 }, // Class 1
new int[] { 1, 1, 0, 1 }, // Class 1
new int[] { 1, 0, 0, 0, 1 }, // Class 1
new int[] { 1, 0, 1 }, // Class 1
new int[] { 1, 1, 0, 1 }, // Class 1
new int[] { 1, 0, 1 }, // Class 1
new int[] { 1, 0, 0, 1 }, // Class 1
new int[] { 1, 0, 0, 0, 1 }, // Class 1
new int[] { 1, 0, 1 }, // Class 1
new int[] { 1, 0, 0, 0, 1 }, // Class 1
};
int[] outputs = new int[]
{
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // First 10 sequences are of class 0
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // Last 10 sequences are of class 1
};
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation <HiddenMarkovClassifier>(size: inputs.Length, folds: 3);
// Define a fitting function using Support Vector Machines. The objective of this
// function is to learn a SVM in the subset of the data indicated by cross-validation.
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// The fitting function is passing the indices of the original set which
// should be considered training data and the indices of the original set
// which should be considered validation data.
// Lets now grab the training data:
var trainingInputs = inputs.Submatrix(indicesTrain);
var trainingOutputs = outputs.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = inputs.Submatrix(indicesValidation);
var validationOutputs = outputs.Submatrix(indicesValidation);
// We are trying to predict two different classes
int classes = 2;
// Each sequence may have up to two symbols (0 or 1)
int symbols = 2;
// Nested models will have two states each
int[] states = new int[] { 2, 2 };
// Creates a new Hidden Markov Model Classifier with the given parameters
HiddenMarkovClassifier classifier = new HiddenMarkovClassifier(classes, states, symbols);
// Create a new learning algorithm to train the sequence classifier
var teacher = new HiddenMarkovClassifierLearning(classifier,
// Train each model until the log-likelihood changes less than 0.001
modelIndex => new BaumWelchLearning(classifier.Models[modelIndex])
{
Tolerance = 0.001,
Iterations = 0
}
);
// Train the sequence classifier using the algorithm
double likelihood = teacher.Run(trainingInputs, trainingOutputs);
double trainingError = teacher.ComputeError(trainingInputs, trainingOutputs);
// Now we can compute the validation error on the validation data:
double validationError = teacher.ComputeError(validationInputs, validationOutputs);
// Return a new information structure containing the model and the errors achieved.
return(new CrossValidationValues <HiddenMarkovClassifier>(classifier, trainingError, validationError));
};
// Compute the cross-validation
var result = crossvalidation.Compute();
// Finally, access the measured performance.
double trainingErrors = result.Training.Mean;
double validationErrors = result.Validation.Mean;
Assert.AreEqual(3, crossvalidation.K);
Assert.AreEqual(0, result.Training.Mean);
Assert.AreEqual(0, result.Validation.Mean);
Assert.AreEqual(3, crossvalidation.Folds.Length);
Assert.AreEqual(3, result.Models.Length);
}
public void CrossvalidationConstructorTest()
{
Accord.Math.Tools.SetupGenerator(0);
// This is a sample code on how to use Cross-Validation
// to assess the performance of Support Vector Machines.
// Consider the example binary data. We will be trying
// to learn a XOR problem and see how well does SVMs
// perform on this data.
double[][] data =
{
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
};
int[] xor = // result of xor for the sample input data
{
-1, 1,
1, -1,
-1, 1,
1, -1,
-1, 1,
1, -1,
-1, 1,
1, -1,
};
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation <KernelSupportVectorMachine>(size: data.Length, folds: 3);
// Define a fitting function using Support Vector Machines. The objective of this
// function is to learn a SVM in the subset of the data indicated by cross-validation.
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// The fitting function is passing the indices of the original set which
// should be considered training data and the indices of the original set
// which should be considered validation data.
// Lets now grab the training data:
var trainingInputs = data.Submatrix(indicesTrain);
var trainingOutputs = xor.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = data.Submatrix(indicesValidation);
var validationOutputs = xor.Submatrix(indicesValidation);
// Create a Kernel Support Vector Machine to operate on the set
var svm = new KernelSupportVectorMachine(new Polynomial(2), 2);
// Create a training algorithm and learn the training data
var smo = new SequentialMinimalOptimization(svm, trainingInputs, trainingOutputs);
double trainingError = smo.Run();
// Now we can compute the validation error on the validation data:
double validationError = smo.ComputeError(validationInputs, validationOutputs);
// Return a new information structure containing the model and the errors achieved.
return(new CrossValidationValues <KernelSupportVectorMachine>(svm, trainingError, validationError));
};
// Compute the cross-validation
var result = crossvalidation.Compute();
// Finally, access the measured performance.
double trainingErrors = result.Training.Mean;
double validationErrors = result.Validation.Mean;
Assert.AreEqual(3, crossvalidation.K);
Assert.AreEqual(0, result.Training.Mean);
Assert.AreEqual(0, result.Validation.Mean);
Assert.AreEqual(3, crossvalidation.Folds.Length);
Assert.AreEqual(3, result.Models.Length);
}
public void NotEnoughSamplesTest1()
{
Accord.Math.Random.Generator.Seed = 0;
int[] labels = Matrix.Vector(10, 1).Concatenate(Matrix.Vector(30, 0));
Vector.Shuffle(labels);
var crossvalidation = new CrossValidation<MulticlassSupportVectorMachine>(size: 40, folds: 10)
{
RunInParallel = false,
Fitting = (int index, int[] indicesTrain, int[] indicesValidation) =>
{
var labelsValidation = labels.Submatrix(indicesValidation);
int countValidation = labelsValidation.Count(x => x == 1);
Assert.AreEqual(2, countValidation);
var labelsTraining = labels.Submatrix(indicesTrain);
int countTraining = labelsTraining.Count(x => x == 1);
Assert.AreEqual(9 * 2, countTraining);
return new CrossValidationValues<MulticlassSupportVectorMachine>(null, 0, 0);
}
};
bool thrown = false;
try { crossvalidation.Compute(); }
catch (Exception) { thrown = true; }
Assert.IsTrue(thrown);
crossvalidation = new CrossValidation<MulticlassSupportVectorMachine>(labels, 2, folds: 10)
{
RunInParallel = false,
Fitting = (int index, int[] indicesTrain, int[] indicesValidation) =>
{
var labelsValidation = labels.Submatrix(indicesValidation);
int countValidation = labelsValidation.Count(x => x == 1);
Assert.AreEqual(1, countValidation);
var labelsTraining = labels.Submatrix(indicesTrain);
int countTraining = labelsTraining.Count(x => x == 1);
Assert.AreEqual(9, countTraining);
return new CrossValidationValues<MulticlassSupportVectorMachine>(null, 0, 0);
}
};
crossvalidation.Compute();
}
private void Test_Load(object sender, EventArgs e)
{
// TODO: This line of code loads data into the 'diabetesDataSetB.ContinuousData' table. You can move, or remove it, as needed.
this.continuousDataTableAdapter.Fill(this.diabetesDataSetB.ContinuousData);
// This is a sample code on how to use Cross-Validation
// to access the performance of Support Vector Machines.
// Consider the example binary data. We will be trying
// to learn a XOR problem and see how well does SVMs
// perform on this data.
double[][] data =
{
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
};
int[] xor = // result of xor for the sample input data
{
-1, 1,
1, -1,
-1, 1,
1, -1,
-1, 1,
1, -1,
-1, 1,
1, -1,
};
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation<KernelSupportVectorMachine>(size: data.Length, folds: 3);
// Define a fitting function using Support Vector Machines. The objective of this
// function is to learn a SVM in the subset of the data dicted by cross-validation.
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// The fitting function is passing the indices of the original set which
// should be considered training data and the indices of the original set
// which should be considered validation data.
// Lets now grab the training data:
var trainingInputs = data.Submatrix(indicesTrain);
var trainingOutputs = xor.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = data.Submatrix(indicesValidation);
var validationOutputs = xor.Submatrix(indicesValidation);
// Create a Kernel Support Vector Machine to operate on the set
var svm = new KernelSupportVectorMachine(new Polynomial(2), 2);
// Create a training algorithm and learn the training data
var smo = new SequentialMinimalOptimization(svm, trainingInputs, trainingOutputs);
double trainingError = smo.Run();
// Now we can compute the validation error on the validation data:
double validationError = smo.ComputeError(validationInputs, validationOutputs);
// Return a new information structure containing the model and the errors achieved.
return new CrossValidationValues<KernelSupportVectorMachine>(svm, trainingError, validationError);
};
//crossvalidation.CreatePartitions(2, data,out xor);
// Compute the cross-validation
var result = crossvalidation.Compute();
// Finally, access the measured performance.
double trainingErrors = result.Training.Mean;
double validationErrors = result.Validation.Mean;
}
private CrossValidationResult _performCrossValidation()
{
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation(size: _inputs.Length, folds: _configuration.CrossValidationNumFolds);
Console.WriteLine("Num Samples: " + crossvalidation.Samples);
// ConcurrentDictionary<string, NodeClassification> nodeClassifications = new ConcurrentDictionary<string, NodeClassification>();
CrossValidationResult cvResult = new CrossValidationResult();
// Define a fitting function using Support Vector Machines. The objective of this
// function is to learn a SVM in the subset of the data indicated by cross-validation.
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// The fitting function is passing the indices of the original set which
// should be considered training data and the indices of the original set
// which should be considered validation data.
// Lets now grab the training data:
var trainingInputs = _inputs.Submatrix(indicesTrain);
var trainingOutputs = _outputs.Submatrix(indicesTrain);
var trainingNames = _names.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = _inputs.Submatrix(indicesValidation);
var validationOutputs = _outputs.Submatrix(indicesValidation);
var validationNames = _names.Submatrix(indicesValidation);
if (validationNames.Intersect <String>(trainingNames).Count() > 0)
{
Console.WriteLine("Warning, Training and Validation Set not disjunct.");
Utility.writeToConsole <String>(validationNames.Intersect(trainingNames).ToArray());
}
//Console.WriteLine("=== TRAINING ===");
//Utility.writeToConsole<String>(trainingNames);
//Utility.writeToConsole<int>(trainingInputs);
//Utility.writeToConsole<int>(trainingOutputs);
//Console.WriteLine("=== VALIDATION ===");
//Utility.writeToConsole<String>(validationNames);
//Utility.writeToConsole<double>(validationInputs);
//Utility.writeToConsole<int>(validationOutputs);
//Console.WriteLine("=== INTERSECTION ===");
//String[] intersection = Utility.Intersection(validationNames, trainingNames);
//Utility.writeToConsole<String>(intersection);
// Create a Kernel Support Vector Machine to operate on the set
var svm = new KernelSupportVectorMachine(_kernel, _inputs[0].Length);
//Accord.MachineLearning.Boosting.Boost<KernelSupportVectorMachine> b;
// Create a training algorithm and learn the training data
var smo = new SequentialMinimalOptimization(svm, trainingInputs, trainingOutputs)
{
// Set learning parameters
Tolerance = _configuration.Tolerance,
PositiveWeight = _configuration.WeightPositiveClass,
NegativeWeight = _configuration.WeightNegativeClass,
UseClassProportions = _configuration.UseComputedWeights,
UseComplexityHeuristic = true
};
//if (!_configuration.UseHeuristicalComplexity)
_smo.Complexity = _configuration.Complexity;
double trainingError = smo.Run();
// Now we can compute the validation error on the validation data:
double validationError = smo.ComputeError(validationInputs, validationOutputs);
// Predictions & Confusion Matrix
List <int> predictions = new List <int>();
List <double> rawPredictions = new List <double>();
int index = 0;
foreach (double[] inputVector in validationInputs)
{
// Compute the decision output for vector
// Console.WriteLine(validationNames[index]);
// Utility.writeToConsole<double>(inputVector);
double rawPrediction = svm.Compute(inputVector);
rawPredictions.Add(rawPrediction);
int prediction = rawPrediction > 0.0d ? +1 : -1;
predictions.Add(prediction);
try
{
// Update Node Classifications
cvResult.AddOrUpdateClassification(validationNames[index], rawPrediction, validationOutputs[index]);
}
catch (IndexOutOfRangeException)
{
Console.WriteLine("Failed to update CV Result: Input Vector larger than Name Vector.");
}
index++;
}
ConfusionMatrix confusionMatrix = new ConfusionMatrix(predictions.ToArray(), validationOutputs, 1, -1);
cvResult.ConfusionMatrices.Add(confusionMatrix);
// Return a new information structure containing the model and the errors achieved.
return(new CrossValidationValues(svm, trainingError, validationError));
};
// Compute the cross-validation
var result = crossvalidation.Compute();
// Finally, access the measured performance.
double trainingErrors = result.Training.Mean;
double validationErrors = result.Validation.Mean;
Console.WriteLine("Training Errors: " + result.Training.Mean);
Console.WriteLine("Validation Errors: " + result.Validation.Mean);
ConfusionMatrix aggregatedConfusionMatrix = ConfusionMatrix.Combine(cvResult.ConfusionMatrices.ToArray());
return(cvResult);
}
private void Test_Load(object sender, EventArgs e)
{
// TODO: This line of code loads data into the 'diabetesDataSetB.ContinuousData' table. You can move, or remove it, as needed.
this.continuousDataTableAdapter.Fill(this.diabetesDataSetB.ContinuousData);
// This is a sample code on how to use Cross-Validation
// to access the performance of Support Vector Machines.
// Consider the example binary data. We will be trying
// to learn a XOR problem and see how well does SVMs
// perform on this data.
double[][] data =
{
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
};
int[] xor = // result of xor for the sample input data
{
-1, 1,
1, -1,
-1, 1,
1, -1,
-1, 1,
1, -1,
-1, 1,
1, -1,
};
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation <KernelSupportVectorMachine>(size: data.Length, folds: 3);
// Define a fitting function using Support Vector Machines. The objective of this
// function is to learn a SVM in the subset of the data dicted by cross-validation.
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// The fitting function is passing the indices of the original set which
// should be considered training data and the indices of the original set
// which should be considered validation data.
// Lets now grab the training data:
var trainingInputs = data.Submatrix(indicesTrain);
var trainingOutputs = xor.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = data.Submatrix(indicesValidation);
var validationOutputs = xor.Submatrix(indicesValidation);
// Create a Kernel Support Vector Machine to operate on the set
var svm = new KernelSupportVectorMachine(new Polynomial(2), 2);
// Create a training algorithm and learn the training data
var smo = new SequentialMinimalOptimization(svm, trainingInputs, trainingOutputs);
double trainingError = smo.Run();
// Now we can compute the validation error on the validation data:
double validationError = smo.ComputeError(validationInputs, validationOutputs);
// Return a new information structure containing the model and the errors achieved.
return(new CrossValidationValues <KernelSupportVectorMachine>(svm, trainingError, validationError));
};
//crossvalidation.CreatePartitions(2, data,out xor);
// Compute the cross-validation
var result = crossvalidation.Compute();
// Finally, access the measured performance.
double trainingErrors = result.Training.Mean;
double validationErrors = result.Validation.Mean;
}
public void CrossvalidationConstructorTest2()
{
Accord.Math.Tools.SetupGenerator(0);
// This is a sample code on how to use Cross-Validation
// to assess the performance of Hidden Markov Models.
// Declare some testing data
int[][] inputs = new int[][]
{
new int[] { 0,1,1,0 }, // Class 0
new int[] { 0,0,1,0 }, // Class 0
new int[] { 0,1,1,1,0 }, // Class 0
new int[] { 0,1,1,1,0 }, // Class 0
new int[] { 0,1,1,0 }, // Class 0
new int[] { 0,1,1,1,0 }, // Class 0
new int[] { 0,1,1,1,0 }, // Class 0
new int[] { 0,1,0,1,0 }, // Class 0
new int[] { 0,1,0 }, // Class 0
new int[] { 0,1,1,0 }, // Class 0
new int[] { 1,0,0,1 }, // Class 1
new int[] { 1,1,0,1 }, // Class 1
new int[] { 1,0,0,0,1 }, // Class 1
new int[] { 1,0,1 }, // Class 1
new int[] { 1,1,0,1 }, // Class 1
new int[] { 1,0,1 }, // Class 1
new int[] { 1,0,0,1 }, // Class 1
new int[] { 1,0,0,0,1 }, // Class 1
new int[] { 1,0,1 }, // Class 1
new int[] { 1,0,0,0,1 }, // Class 1
};
int[] outputs = new int[]
{
0,0,0,0,0,0,0,0,0,0, // First 10 sequences are of class 0
1,1,1,1,1,1,1,1,1,1, // Last 10 sequences are of class 1
};
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation<HiddenMarkovClassifier>(size: inputs.Length, folds: 3);
// Define a fitting function using Support Vector Machines. The objective of this
// function is to learn a SVM in the subset of the data indicated by cross-validation.
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// The fitting function is passing the indices of the original set which
// should be considered training data and the indices of the original set
// which should be considered validation data.
// Lets now grab the training data:
var trainingInputs = inputs.Submatrix(indicesTrain);
var trainingOutputs = outputs.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = inputs.Submatrix(indicesValidation);
var validationOutputs = outputs.Submatrix(indicesValidation);
// We are trying to predict two different classes
int classes = 2;
// Each sequence may have up to two symbols (0 or 1)
int symbols = 2;
// Nested models will have two states each
int[] states = new int[] { 2, 2 };
// Creates a new Hidden Markov Model Classifier with the given parameters
HiddenMarkovClassifier classifier = new HiddenMarkovClassifier(classes, states, symbols);
// Create a new learning algorithm to train the sequence classifier
var teacher = new HiddenMarkovClassifierLearning(classifier,
// Train each model until the log-likelihood changes less than 0.001
modelIndex => new BaumWelchLearning(classifier.Models[modelIndex])
{
Tolerance = 0.001,
Iterations = 0
}
);
// Train the sequence classifier using the algorithm
double likelihood = teacher.Run(trainingInputs, trainingOutputs);
double trainingError = teacher.ComputeError(trainingInputs, trainingOutputs);
// Now we can compute the validation error on the validation data:
double validationError = teacher.ComputeError(validationInputs, validationOutputs);
// Return a new information structure containing the model and the errors achieved.
return new CrossValidationValues<HiddenMarkovClassifier>(classifier, trainingError, validationError);
};
// Compute the cross-validation
var result = crossvalidation.Compute();
// Finally, access the measured performance.
double trainingErrors = result.Training.Mean;
double validationErrors = result.Validation.Mean;
Assert.AreEqual(3, crossvalidation.K);
Assert.AreEqual(0, result.Training.Mean);
Assert.AreEqual(0.055555555555555552, result.Validation.Mean);
Assert.AreEqual(3, crossvalidation.Folds.Length);
Assert.AreEqual(3, result.Models.Length);
}
public void KNearestNeighbor_CrossValidation()
{
// Create some sample learning data. In this data,
// the first two instances belong to a class, the
// four next belong to another class and the last
// three to yet another.
double[][] inputs =
{
// The first two are from class 0
new double[] { -5, -2, -1 },
new double[] { -5, -5, -6 },
// The next four are from class 1
new double[] { 2, 1, 1 },
new double[] { 1, 1, 2 },
new double[] { 1, 2, 2 },
new double[] { 3, 1, 2 },
// The last three are from class 2
new double[] { 11, 5, 4 },
new double[] { 15, 5, 6 },
new double[] { 10, 5, 6 },
};
int[] outputs =
{
0, 0, // First two from class 0
1, 1, 1, 1, // Next four from class 1
2, 2, 2 // Last three from class 2
};
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation(size: inputs.Length, folds: 3);
// Define a fitting function using Support Vector Machines. The objective of this
// function is to learn a SVM in the subset of the data indicated by cross-validation.
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// The fitting function is passing the indices of the original set which
// should be considered training data and the indices of the original set
// which should be considered validation data.
// Lets now grab the training data:
var trainingInputs = inputs.Submatrix(indicesTrain);
var trainingOutputs = outputs.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = inputs.Submatrix(indicesValidation);
var validationOutputs = outputs.Submatrix(indicesValidation);
// Now we will create the K-Nearest Neighbors algorithm. For this
// example, we will be choosing k = 4. This means that, for a given
// instance, its nearest 4 neighbors will be used to cast a decision.
KNearestNeighbors knn = new KNearestNeighbors(k: 4, classes: 3,
inputs: inputs, outputs: outputs);
// After the algorithm has been created, we can classify instances:
int[] train_predicted = trainingInputs.Apply(knn.Compute);
int[] test_predicted = validationInputs.Apply(knn.Compute);
// Compute classification error
var cmTrain = new ConfusionMatrix(train_predicted, trainingOutputs);
double trainingAcc = cmTrain.Accuracy;
// Now we can compute the validation error on the validation data:
var cmTest = new ConfusionMatrix(test_predicted, validationOutputs);
double validationAcc = cmTest.Accuracy;
// Return a new information structure containing the model and the errors achieved.
return(new CrossValidationValues(knn, trainingAcc, validationAcc));
};
// Compute the cross-validation
var result = crossvalidation.Compute();
// Finally, access the measured performance.
double trainingAccs = result.Training.Mean;
double validationAccs = result.Validation.Mean;
Assert.AreEqual(1, trainingAccs);
Assert.AreEqual(1, validationAccs);
}
public void KNearestNeighbor_CrossValidation()
{
// Create some sample learning data. In this data,
// the first two instances belong to a class, the
// four next belong to another class and the last
// three to yet another.
double[][] inputs =
{
// The first two are from class 0
new double[] { -5, -2, -1 },
new double[] { -5, -5, -6 },
// The next four are from class 1
new double[] { 2, 1, 1 },
new double[] { 1, 1, 2 },
new double[] { 1, 2, 2 },
new double[] { 3, 1, 2 },
// The last three are from class 2
new double[] { 11, 5, 4 },
new double[] { 15, 5, 6 },
new double[] { 10, 5, 6 },
};
int[] outputs =
{
0, 0, // First two from class 0
1, 1, 1, 1, // Next four from class 1
2, 2, 2 // Last three from class 2
};
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation(size: inputs.Length, folds: 3);
// Define a fitting function using Support Vector Machines. The objective of this
// function is to learn a SVM in the subset of the data indicated by cross-validation.
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// The fitting function is passing the indices of the original set which
// should be considered training data and the indices of the original set
// which should be considered validation data.
// Lets now grab the training data:
var trainingInputs = inputs.Submatrix(indicesTrain);
var trainingOutputs = outputs.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = inputs.Submatrix(indicesValidation);
var validationOutputs = outputs.Submatrix(indicesValidation);
// Now we will create the K-Nearest Neighbors algorithm. For this
// example, we will be choosing k = 4. This means that, for a given
// instance, its nearest 4 neighbors will be used to cast a decision.
KNearestNeighbors knn = new KNearestNeighbors(k: 4, classes: 3,
inputs: inputs, outputs: outputs);
// After the algorithm has been created, we can classify instances:
int[] train_predicted = trainingInputs.Apply(knn.Compute);
int[] test_predicted = validationInputs.Apply(knn.Compute);
// Compute classification error
var cmTrain = new ConfusionMatrix(train_predicted, trainingOutputs);
double trainingAcc = cmTrain.Accuracy;
// Now we can compute the validation error on the validation data:
var cmTest = new ConfusionMatrix(test_predicted, validationOutputs);
double validationAcc = cmTest.Accuracy;
// Return a new information structure containing the model and the errors achieved.
return new CrossValidationValues(knn, trainingAcc, validationAcc);
};
// Compute the cross-validation
var result = crossvalidation.Compute();
// Finally, access the measured performance.
double trainingAccs = result.Training.Mean;
double validationAccs = result.Validation.Mean;
Assert.AreEqual(1, trainingAccs);
Assert.AreEqual(1, validationAccs);
}
public override Task <GridSearchParameterCollection> GridSearchAsync(ClassificationModel classificationModel)
{
return(Task.Factory.StartNew(() =>
{
// Declare the parameters and ranges to be searched
List <GridSearchRange> ranges = new List <GridSearchRange>
{
new GridSearchRange("complexity", new[] { 150.0, 100.0, 50, 10, 1 }),
};
switch (Kernel)
{
case Kernel.Gaussian:
ranges.Add(new GridSearchRange("gamma", new[] { 0.1, 1.0, 2.0, 5.0, 10.0, 20.0 }));
break;
case Kernel.Polynomial:
ranges.Add(new GridSearchRange("degree", new[] { 1.0, 2.0, 3.0, 4.0 }));
break;
}
int numFeatures = classificationModel.FeatureVectors.Count;
double[][] input = new double[numFeatures][];
int[] responses = new int[numFeatures];
for (int featureIndex = 0; featureIndex < classificationModel.FeatureVectors.Count; ++featureIndex)
{
var featureVector = classificationModel.FeatureVectors[featureIndex];
input[featureIndex] = Array.ConvertAll(featureVector.FeatureVector.BandIntensities, s => (double)s / ushort.MaxValue);
responses[featureIndex] = (int)featureVector.FeatureClass;
}
// Instantiate a new Grid Search algorithm for Kernel Support Vector Machines
var gridsearch = new GridSearch <MulticlassSupportVectorMachine <Gaussian> >(ranges.ToArray());
// Set the fitting function for the algorithm
gridsearch.Fitting = delegate(GridSearchParameterCollection parameters, out double error)
{
// The parameters to be tried will be passed as a function parameter.
double complexity = parameters["complexity"].Value;
double gamma = parameters.Contains("gamma") ? parameters["gamma"].Value : 0;
int degree = parameters.Contains("degree") ? (int)parameters["degree"].Value : 0;
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation(size: input.Length, folds: 10);
// Define a fitting function using Support Vector Machines. The objective of this
// function is to learn a SVM in the subset of the data indicated by cross-validation.
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// Lets now grab the training data:
var trainingInputs = input.Get(indicesTrain);
var trainingOutputs = responses.Get(indicesTrain);
// And now the validation data:
var validationInputs = input.Get(indicesValidation);
var validationOutputs = responses.Get(indicesValidation);
int[] predictedTraining;
int[] predictedValidation;
TrainAndPredict(complexity, gamma, degree, trainingInputs, trainingOutputs, validationInputs, out predictedTraining, out predictedValidation);
double trainingError = new ZeroOneLoss(trainingOutputs).Loss(predictedTraining);
double validationError = new ZeroOneLoss(validationOutputs).Loss(predictedValidation);
// Return a new information structure containing the model and the errors achieved.
return new CrossValidationValues(trainingError, validationError);
};
// Compute the cross-validation
var result = crossvalidation.Compute();
// Finally, access the measured performance.
double trainingErrors = result.Training.Mean;
double validationErrors = result.Validation.Mean;
error = validationErrors;
return null; // Return the current model
};
// Declare some out variables to pass to the grid search algorithm
GridSearchParameterCollection bestParameters;
double minError;
// Compute the grid search to find the best Support Vector Machine
gridsearch.Compute(out bestParameters, out minError);
return bestParameters;
}));
}
public void CrossvalidationConstructorTest()
{
Accord.Math.Tools.SetupGenerator(0);
// This is a sample code on how to use Cross-Validation
// to assess the performance of Support Vector Machines.
// Consider the example binary data. We will be trying
// to learn a XOR problem and see how well does SVMs
// perform on this data.
double[][] data =
{
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
new double[] { -1, -1 }, new double[] { 1, -1 },
new double[] { -1, 1 }, new double[] { 1, 1 },
};
int[] xor = // result of xor for the sample input data
{
-1, 1,
1, -1,
-1, 1,
1, -1,
-1, 1,
1, -1,
-1, 1,
1, -1,
};
// Create a new Cross-validation algorithm passing the data set size and the number of folds
var crossvalidation = new CrossValidation<KernelSupportVectorMachine>(size: data.Length, folds: 3);
// Define a fitting function using Support Vector Machines. The objective of this
// function is to learn a SVM in the subset of the data indicated by cross-validation.
crossvalidation.Fitting = delegate(int k, int[] indicesTrain, int[] indicesValidation)
{
// The fitting function is passing the indices of the original set which
// should be considered training data and the indices of the original set
// which should be considered validation data.
// Lets now grab the training data:
var trainingInputs = data.Submatrix(indicesTrain);
var trainingOutputs = xor.Submatrix(indicesTrain);
// And now the validation data:
var validationInputs = data.Submatrix(indicesValidation);
var validationOutputs = xor.Submatrix(indicesValidation);
// Create a Kernel Support Vector Machine to operate on the set
var svm = new KernelSupportVectorMachine(new Polynomial(2), 2);
// Create a training algorithm and learn the training data
var smo = new SequentialMinimalOptimization(svm, trainingInputs, trainingOutputs);
double trainingError = smo.Run();
// Now we can compute the validation error on the validation data:
double validationError = smo.ComputeError(validationInputs, validationOutputs);
// Return a new information structure containing the model and the errors achieved.
return new CrossValidationValues<KernelSupportVectorMachine>(svm, trainingError, validationError);
};
// Compute the cross-validation
var result = crossvalidation.Compute();
// Finally, access the measured performance.
double trainingErrors = result.Training.Mean;
double validationErrors = result.Validation.Mean;
Assert.AreEqual(3, crossvalidation.K);
Assert.AreEqual(0, result.Training.Mean);
Assert.AreEqual(0, result.Validation.Mean);
Assert.AreEqual(3, crossvalidation.Folds.Length);
Assert.AreEqual(3, result.Models.Length);
}
public void FittingTest()
{
int[] folds = CrossValidation.Splittings(100, 10);
int[] samples = Matrix.Indices(0, 100);
CrossValidation val = new CrossValidation(folds, 10);
val.RunInParallel = false;
int current = 0;
val.Fitting = (k, trainingSamples, validationSamples) =>
{
Assert.AreEqual(current, k);
Assert.AreEqual(90, trainingSamples.Length);
Assert.AreEqual(10, validationSamples.Length);
int[] trainingSet = samples.Submatrix(trainingSamples);
int[] validationSet = samples.Submatrix(validationSamples);
for (int i = 0; i < trainingSet.Length; i++)
Assert.AreEqual(samples[trainingSamples[i]], trainingSet[i]);
for (int i = 0; i < validationSet.Length; i++)
Assert.AreEqual(samples[validationSamples[i]], validationSet[i]);
current++;
return new CrossValidationValues<object>(new object(), k, 2 * k);
};
var result = val.Compute();
Assert.AreEqual(10, current);
Assert.AreEqual(4.5, result.Training.Mean);
Assert.AreEqual(9.0, result.Validation.Mean);
Assert.AreEqual(
2 * result.Training.StandardDeviation,
result.Validation.StandardDeviation);
Assert.AreEqual(val.Folds.Length, result.Training.Sizes.Length);
Assert.AreEqual(val.Folds.Length, result.Validation.Sizes.Length);
for (int i = 0; i < result.Training.Sizes.Length; i++)
Assert.AreEqual(90, result.Training.Sizes[i]);
for (int i = 0; i < result.Validation.Sizes.Length; i++)
Assert.AreEqual(10, result.Validation.Sizes[i]);
}
private void button1_Click(object sender, EventArgs e)
{
// Creates a matrix from the source data table
double[,] sourceMatrix = (dgvLearningSource.DataSource as DataTable).ToMatrix(out sourceColumns);
// Get only the input vector values
var inputs = sourceMatrix.Submatrix(0, sourceMatrix.GetLength(0) - 1, 0, 1).ToArray();
// Get only the label outputs
var outputs = new int[sourceMatrix.GetLength(0)];
for (int i = 0; i < outputs.Length; i++)
outputs[i] = (int)sourceMatrix[i, 2];
var cv = new CrossValidation<KernelSupportVectorMachine>(inputs.Length, 10);
cv.Fitting = (int k, int[] training, int[] testing) =>
{
var trainingInputs = inputs.Submatrix(training);
var trainingOutputs = outputs.Submatrix(training);
var testingInputs = inputs.Submatrix(testing);
var testingOutputs = outputs.Submatrix(testing);
// Create the specified Kernel
IKernel kernel = getKernel();
// Creates the Support Vector Machine using the selected kernel
var svm = new KernelSupportVectorMachine(kernel, 2);
// Creates a new instance of the SMO Learning Algortihm
var smo = new SequentialMinimalOptimization(svm, trainingInputs, trainingOutputs);
// Set learning parameters
smo.Complexity = (double)numC.Value;
smo.Tolerance = (double)numT.Value;
// Run
double trainingError = smo.Run();
double validationError = smo.ComputeError(testingInputs, testingOutputs);
return new CrossValidationValues<KernelSupportVectorMachine>(svm, trainingError, validationError);
};
var result = cv.Compute();
}
