public void ConstructorTest()
{
var invchisq = new InverseChiSquareDistribution(degreesOfFreedom: 7);
double mean = invchisq.Mean; // 0.2
double median = invchisq.Median; // 6.345811068141737
double var = invchisq.Variance; // 75
double mode = invchisq.Mode; // 0.1111111111111111
double cdf = invchisq.DistributionFunction(x: 6.27); // 0.50860033566176044
double pdf = invchisq.ProbabilityDensityFunction(x: 6.27); // 0.0000063457380298844403
double lpdf = invchisq.LogProbabilityDensityFunction(x: 6.27); // -11.967727146795536
double ccdf = invchisq.ComplementaryDistributionFunction(x: 6.27); // 0.49139966433823956
double icdf = invchisq.InverseDistributionFunction(p: cdf); // 6.2699998329362963
double hf = invchisq.HazardFunction(x: 6.27); // 0.000012913598625327002
double chf = invchisq.CumulativeHazardFunction(x: 6.27); // 0.71049750196765715
string str = invchisq.ToString(); // "Inv-χ²(x; df = 7)"
Assert.AreEqual(0.2, mean, 1e-10);
Assert.AreEqual(6.345811068141737, median, 1e-6);
Assert.AreEqual(75, var);
Assert.AreEqual(0.1111111111111111, mode);
Assert.AreEqual(0.71049750196765715, chf);
Assert.AreEqual(0.50860033566176044, cdf);
Assert.AreEqual(0.0000063457380298844403, pdf);
Assert.AreEqual(-11.967727146795536, lpdf);
Assert.AreEqual(0.000012913598625327002, hf);
Assert.AreEqual(0.49139966433823956, ccdf);
Assert.AreEqual(6.2699998329362963, icdf, 1e-6);
Assert.AreEqual("Inv-χ²(x; df = 7)", str);
var range1 = invchisq.GetRange(0.95);
var range2 = invchisq.GetRange(0.99);
var range3 = invchisq.GetRange(0.01);
Assert.AreEqual(2.1673499092513264, range1.Min);
Assert.AreEqual(14.067140449765922, range1.Max);
Assert.AreEqual(1.2390421125300894, range2.Min);
Assert.AreEqual(18.475307115523769, range2.Max);
Assert.AreEqual(1.2390421125300894, range3.Min);
Assert.AreEqual(18.475307115523773, range3.Max);
}