public void NaiveBayesConstructorTest4()
{
int classes = 2;
int inputCount = 3;
double[] priors = { 0.4, 0.6 };
UniformDiscreteDistribution initial = new UniformDiscreteDistribution(0, 3);
var target = new NaiveBayes<UniformDiscreteDistribution>(classes, inputCount, initial, priors);
Assert.AreEqual(classes, target.ClassCount);
Assert.AreEqual(inputCount, target.InputCount);
Assert.AreEqual(priors.Length, target.Priors.Length);
Assert.AreEqual(0.4, target.Priors[0]);
Assert.AreEqual(0.6, target.Priors[1]);
Assert.AreEqual(2, target.Distributions.GetLength(0));
Assert.AreEqual(3, target.Distributions.GetLength(1));
for (int i = 0; i < classes; i++)
{
for (int j = 0; j < inputCount; j++)
{
Assert.AreNotSame(initial, target.Distributions[i, j]);
Assert.AreEqual(0, target.Distributions[i, j].Minimum);
Assert.AreEqual(3, target.Distributions[i, j].Maximum);
}
}
}
public void ConstructorTest()
{
// Create an uniform (discrete) distribution in [2, 6]
var dist = new UniformDiscreteDistribution(a: 2, b: 6);
// Common measures
double mean = dist.Mean; // 4.0
double median = dist.Median; // 4.0
double var = dist.Variance; // 1.3333333333333333
// Cumulative distribution functions
double cdf = dist.DistributionFunction(k: 2); // 0.2
double ccdf = dist.ComplementaryDistributionFunction(k: 2); // 0.8
// Probability mass functions
double pmf1 = dist.ProbabilityMassFunction(k: 4); // 0.2
double pmf2 = dist.ProbabilityMassFunction(k: 5); // 0.2
double pmf3 = dist.ProbabilityMassFunction(k: 6); // 0.2
double lpmf = dist.LogProbabilityMassFunction(k: 2); // -1.6094379124341003
// Quantile function
int icdf1 = dist.InverseDistributionFunction(p: 0.17); // 2
int icdf2 = dist.InverseDistributionFunction(p: 0.46); // 4
int icdf3 = dist.InverseDistributionFunction(p: 0.87); // 6
// Hazard (failure rate) functions
double hf = dist.HazardFunction(x: 4); // 0.5
double chf = dist.CumulativeHazardFunction(x: 4); // 0.916290731874155
// String representation
string str = dist.ToString(CultureInfo.InvariantCulture); // "U(x; a = 2, b = 6)"
Assert.AreEqual(4.0, mean);
Assert.AreEqual(4.0, median);
Assert.AreEqual(1.3333333333333333, var);
Assert.AreEqual(0.916290731874155, chf, 1e-10);
Assert.AreEqual(0.2, cdf);
Assert.AreEqual(0.2, pmf1);
Assert.AreEqual(0.2, pmf2);
Assert.AreEqual(0.2, pmf3);
Assert.AreEqual(-1.6094379124341003, lpmf);
Assert.AreEqual(0.5, hf);
Assert.AreEqual(0.8, ccdf);
Assert.AreEqual(2, icdf1);
Assert.AreEqual(4, icdf2);
Assert.AreEqual(6, icdf3);
Assert.AreEqual("U(x; a = 2, b = 6)", str);
var range1 = dist.GetRange(0.95);
var range2 = dist.GetRange(0.99);
var range3 = dist.GetRange(0.01);
Assert.AreEqual(2, range1.Min);
Assert.AreEqual(6, range1.Max);
Assert.AreEqual(2.0, range2.Min);
Assert.AreEqual(6, range2.Max);
Assert.AreEqual(2.0, range3.Min);
Assert.AreEqual(6, range3.Max);
}
public void GetRangeTest()
{
var u = new UniformDiscreteDistribution(-8, 7);
var range = u.GetRange(0.99);
Assert.AreEqual(-8, range.Min);
Assert.AreEqual(7, range.Max);
}
public void IntervalTest()
{
var target = new UniformDiscreteDistribution(-10, 10);
for (int k = -15; k < 15; k++)
{
double expected = target.ProbabilityMassFunction(k);
double a = target.DistributionFunction(k);
double b = target.DistributionFunction(k - 1);
double c = a - b;
Assert.AreEqual(expected, c, 1e-15);
Assert.AreEqual(c, target.DistributionFunction(k - 1, k), 1e-15);
}
}
public void PosteriorTest1()
{
// Example from http://ai.stanford.edu/~serafim/CS262_2007/notes/lecture5.pdf
double[,] A =
{
{ 0.95, 0.05 }, // fair dice state
{ 0.05, 0.95 }, // loaded dice state
};
double[,] B =
{
{ 1 / 6.0, 1 / 6.0, 1 / 6.0, 1 / 6.0, 1 / 6.0, 1 / 6.0 }, // fair dice probabilities
{ 1 / 10.0, 1 / 10.0, 1 / 10.0, 1 / 10.0, 1 / 10.0, 1 / 2.0 }, // loaded probabilities
};
double[] pi = { 0.5, 0.5 };
var hmm = HiddenMarkovModel.CreateGeneric(A, B, pi);
int[] x = new int[] { 1, 2, 1, 5, 6, 2, 1, 5, 2, 4 }.Subtract(1);
int[] y = new int[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
double py = Math.Exp(hmm.Evaluate(x, y));
Assert.AreEqual(0.00000000521158647211, py, 1e-16);
x = new int[] { 1, 2, 1, 5, 6, 2, 1, 5, 2, 4 }.Subtract(1);
y = new int[] { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 };
py = Math.Exp(hmm.Evaluate(x, y));
Assert.AreEqual(0.00000000015756235243, py, 1e-16);
Accord.Math.Tools.SetupGenerator(0);
var u = new UniformDiscreteDistribution(0, 6);
int[] sequence = u.Generate(1000);
int start = 120;
int end = 150;
for (int i = start; i < end; i += 2)
sequence[i] = 5;
// Predict the next observation in sequence
int[] path;
double[][] p = hmm.Posterior(sequence, out path);
for (int i = 0; i < path.Length; i++)
Assert.AreEqual(1, p[i][0] + p[i][1], 1e-10);
int loaded = 0;
for (int i = 0; i < start; i++)
if (p[i][1] > 0.95)
loaded++;
Assert.AreEqual(0, loaded);
loaded = 0;
for (int i = start; i < end; i++)
if (p[i][1] > 0.95)
loaded++;
Assert.IsTrue(loaded > 15);
loaded = 0;
for (int i = end; i < p.Length; i++)
if (p[i][1] > 0.95)
loaded++;
Assert.AreEqual(0, loaded);
}