Accord.Statistics.Distributions.Univariate.DegenerateDistribution.ProbabilityMassFunction C# (CSharp) Method

ProbabilityMassFunction() public method

Gets the probability mass function (pmf) for this distribution evaluated at point x.
The Probability Mass Function (PMF) describes the probability that a given value x will occur.
public ProbabilityMassFunction ( int k ) : double
k int A single point in the distribution range.
return double
        public override double ProbabilityMassFunction(int k)
        {
            if (k == k0)
                return 1;
            return 0;
        }

Usage Example

        public void ConstructorTest()
        {
            var dist = new DegenerateDistribution(value: 2);

            double mean = dist.Mean;     // 2
            double median = dist.Median; // 2
            double mode = dist.Mode;     // 2
            double var = dist.Variance;  // 1

            double cdf1 = dist.DistributionFunction(k: 1);   // 0
            double cdf2 = dist.DistributionFunction(k: 2);   // 1

            double pdf1 = dist.ProbabilityMassFunction(k: 1); // 0
            double pdf2 = dist.ProbabilityMassFunction(k: 2); // 1
            double pdf3 = dist.ProbabilityMassFunction(k: 3); // 0

            double lpdf = dist.LogProbabilityMassFunction(k: 2); // 0
            double ccdf = dist.ComplementaryDistributionFunction(k: 2); // 0.0

            int icdf1 = dist.InverseDistributionFunction(p: 0.0); // 3
            int icdf2 = dist.InverseDistributionFunction(p: 0.7); // 3
            int icdf3 = dist.InverseDistributionFunction(p: 1.0); // 2

            double hf = dist.HazardFunction(x: 0); // 0.0
            double chf = dist.CumulativeHazardFunction(x: 0); // 0.0

            string str = dist.ToString(CultureInfo.InvariantCulture); // Degenerate(x; k0 = 2)

            Assert.AreEqual(2, mean);
            Assert.AreEqual(2, median);
            Assert.AreEqual(2, mode);
            Assert.AreEqual(0, var);
            Assert.AreEqual(0, chf);
            Assert.AreEqual(0, cdf1);
            Assert.AreEqual(1, cdf2);
            Assert.AreEqual(0, pdf1);
            Assert.AreEqual(1, pdf2);
            Assert.AreEqual(0, pdf3);
            Assert.AreEqual(0, lpdf);
            Assert.AreEqual(0, hf);
            Assert.AreEqual(0, ccdf);
            Assert.AreEqual(1, icdf1);
            Assert.AreEqual(3, icdf2);
            Assert.AreEqual(2, icdf3);
            Assert.AreEqual("Degenerate(x; k0 = 2)", str);

            var range1 = dist.GetRange(0.95);
            var range2 = dist.GetRange(0.99);
            var range3 = dist.GetRange(0.01);

            Assert.AreEqual(1.0, range1.Min);
            Assert.AreEqual(3.0, range1.Max);
            Assert.AreEqual(1.0, range2.Min);
            Assert.AreEqual(3.0, range2.Max);
            Assert.AreEqual(1.0, range3.Min);
            Assert.AreEqual(3.0, range3.Max);
        }