/// <summary>Initializes a new instance of the <see cref="Algorithm"/> class.
/// </summary>
/// <param name="gaussLaguerreIntegrator">The <see cref="GaussLaguerreIntegrator"/> object which serves as factory for the current object.</param>
internal Algorithm(GaussLaguerreIntegrator gaussLaguerreIntegrator)
{
m_IntegratorFactory = gaussLaguerreIntegrator;
if (gaussLaguerreIntegrator.m_AlphaIsZero == true)
{
WeightFunction = OneDimNumericalIntegrator.WeightFunction.Create(x => Math.Exp(-x));
}
else
{
WeightFunction = OneDimNumericalIntegrator.WeightFunction.Create(x => Math.Pow(x, m_IntegratorFactory.Alpha) * Math.Exp(-x));
}
}
public void GetValue_ExpOfMinusX_BenchmarkResult(
[Values(5, 10, 22)]
int alpha,
[Values(100, 125)]
int initialOrder,
[Values(5, 10, 25)]
int orderStepSize)
{
var gaussLaguerreIntegrator = new GaussLaguerreIntegrator(alpha, initialOrder, orderStepSize);
var numericalIntegrator = gaussLaguerreIntegrator.Create();
numericalIntegrator.FunctionToIntegrate = x => Math.Exp(-x); // i.e. \int_0^\infty exp(-2*x) * x^alpha
double expected = GetFaculty(alpha) / Math.Pow(2, alpha + 1); // see for example § 21.6.2 "Taschenbuch der Mathematik", Bronstein, Semendjajew, Musiol, Mühlig, 1995
double actual = numericalIntegrator.GetValue();
Assert.That(actual, Is.EqualTo(expected).Within(1E-7).Percent, String.Format("1-dimensional integrator {0}.", numericalIntegrator.Factory.Name));
}
public void GetValueWithState_One_BenchmarkResult(
[Values(5, 10, 22)]
int alpha,
[Values(100, 125)]
int initialOrder,
[Values(5, 10, 25)]
int orderStepSize)
{
var gaussLaguerreIntegrator = new GaussLaguerreIntegrator(alpha, initialOrder, orderStepSize);
var numericalIntegrator = gaussLaguerreIntegrator.Create();
numericalIntegrator.FunctionToIntegrate = x => 1.0;
double expected = GetFaculty(alpha); // see for example § 21.6.2 "Taschenbuch der Mathematik", Bronstein, Semendjajew, Musiol, Mühlig, 1995
double actual;
OneDimNumericalIntegrator.State state = numericalIntegrator.GetValue(out actual);
Assert.That(actual, Is.EqualTo(expected).Within(1E-7).Percent, String.Format("1-dimensional integrator {0}; state: {1}.", numericalIntegrator.Factory.Name, state.ToString()));
}
