public void FindExtremaNegativeGamma()
{
// https://en.wikipedia.org/wiki/Particular_values_of_the_Gamma_function#Other_constants
Tuple <double, double>[] extrema = new Tuple <double, double>[] {
Tuple.Create(-0.5040830082644554092582693045, -3.5446436111550050891219639933),
Tuple.Create(-1.5734984731623904587782860437, 2.3024072583396801358235820396),
Tuple.Create(-2.6107208684441446500015377157, -0.8881363584012419200955280294),
Tuple.Create(-3.6352933664369010978391815669, 0.2451275398343662504382300889)
};
foreach (Tuple <double, double> extremum in extrema)
{
// We use brackets since we know the extremum must lie between the singularities.
// We should be able to use the actual singularities at endpoints, but this doesn't work; look into it.
Interval bracket = Interval.FromEndpoints(Math.Floor(extremum.Item1) + 0.01, Math.Ceiling(extremum.Item1) - 0.01);
Extremum result;
if (extremum.Item2 < 0.0)
{
result = FunctionMath.FindMaximum(AdvancedMath.Gamma, bracket);
}
else
{
result = FunctionMath.FindMinimum(AdvancedMath.Gamma, bracket);
}
Assert.IsTrue(result.Bracket.OpenContains(extremum.Item1));
Assert.IsTrue(result.Bracket.OpenContains(result.Location));
Assert.IsTrue(TestUtilities.IsNearlyEqual(result.Value, extremum.Item2));
}
}
public void FindMaximaFromPoint()
{
foreach (TestExtremum testExtremum in testMaxima)
{
Extremum extremum = FunctionMath.FindMaximum(testExtremum.Function, testExtremum.Interval.Midpoint);
Assert.IsTrue(TestUtilities.IsNearlyEqual(extremum.Location, testExtremum.Location, Math.Sqrt(TestUtilities.TargetPrecision)));
Assert.IsTrue(TestUtilities.IsNearlyEqual(extremum.Value, testExtremum.Value, TestUtilities.TargetPrecision));
}
}
