Accord.Tests.Statistics.GammaDistributionTest.DensityFunctionTest C# (CSharp) Method

        public void DensityFunctionTest()
        {
            double shape = 0.4;
            double scale = 4.2;

            double[] pdf = 
            {
                double.PositiveInfinity, 0.987114, 0.635929, 0.486871, 0.400046,
                0.341683, 0.299071, 0.266236, 0.239956, 0.218323, 0.200126
            };

            GammaDistribution target = new GammaDistribution(scale, shape);

            for (int i = 0; i < 11; i++)
            {
                double x = i / 10.0;
                double actual = target.ProbabilityDensityFunction(x);
                double expected = pdf[i];

                Assert.AreEqual(expected, actual, 1e-6);
                Assert.IsFalse(double.IsNaN(actual));

                double logActual = target.LogProbabilityDensityFunction(x);
                double logExpected = Math.Log(pdf[i]);

                Assert.AreEqual(logExpected, logActual, 1e-5);
                Assert.IsFalse(double.IsNaN(logActual));
            }
        }