public void ConstructorTest1()
{
// If p=2 the distribution reduces to the von Mises distribution on the circle.
double kappa = 4.2;
var vm = new VonMisesDistribution(0, kappa);
var target = new VonMisesFisherDistribution(new double[] { -1, 0 }, kappa);
double s = Math.Sqrt(2) / 2;
double[] mean = target.Mean;
double a000 = target.ProbabilityDensityFunction(new double[] { +1, +0 });
double a045 = target.ProbabilityDensityFunction(new double[] { +s, +s });
double a090 = target.ProbabilityDensityFunction(new double[] { +0, +1 });
double a135 = target.ProbabilityDensityFunction(new double[] { -s, +s });
double a180 = target.ProbabilityDensityFunction(new double[] { -1, +0 });
double a225 = target.ProbabilityDensityFunction(new double[] { -s, -s });
double a270 = target.ProbabilityDensityFunction(new double[] { +0, -1 });
double a315 = target.ProbabilityDensityFunction(new double[] { +s, -s });
double a360 = target.ProbabilityDensityFunction(new double[] { +1, +0 });
double offset = -Math.PI;
double e000 = vm.ProbabilityDensityFunction(offset + 0);
double e045 = vm.ProbabilityDensityFunction(offset + Math.PI / 4);
double e090 = vm.ProbabilityDensityFunction(offset + Math.PI / 2);
double e135 = vm.ProbabilityDensityFunction(offset + Math.PI * (3 / 4.0));
double e180 = vm.ProbabilityDensityFunction(offset + Math.PI);
double e225 = vm.ProbabilityDensityFunction(offset + Math.PI * (5 / 4.0));
double e270 = vm.ProbabilityDensityFunction(offset + Math.PI * (3 / 2.0));
double e315 = vm.ProbabilityDensityFunction(offset + Math.PI * (7 / 4.0));
double e360 = vm.ProbabilityDensityFunction(offset + Math.PI * 2);
Assert.AreEqual(e000, a000, 1e-8);
Assert.AreEqual(e045, a045, 1e-8);
Assert.AreEqual(e090, a090, 1e-8);
Assert.AreEqual(e135, a135, 1e-8);
Assert.AreEqual(e180, a180, 1e-8);
Assert.AreEqual(e225, a225, 1e-8);
Assert.AreEqual(e270, a270, 1e-8);
Assert.AreEqual(e315, a315, 1e-8);
Assert.AreEqual(e360, a360, 1e-8);
}
