/// <summary>
/// Finds all real roots of polynomial.
/// </summary>
/// <param name="coeficents">The coefficients of polynomial.</param>
/// <param name="error">The error tollerance, actual roots are further polished to give
/// much better approximation (around 1/100 of unpolished).</param>
/// <returns>List of zeros.</returns>
public static List <double> RealRoots([NotNull] double[] coeficents, Intervald range, double error)
{
// For now, replace by Laguerre when implemented.
return(RootFinder.MultiBisectionAndPolish(
Polynomial.CreateFunctiond(coeficents),
Polynomial.CreateFunctiond(Polynomial.Differentiate(coeficents)),
range, error, error * 0.01));
}
public void MultiBisection()
{
List <double> roots = RootFinder.MultiBisection(delegate(double x)
{ return(x * x * x + 2.0 * x * x - x - 2.0); }, new Intervald(-4.0, 2.0), 0.01);
roots.Sort();
Assert.AreEqual(3, roots.Count);
Assert.IsTrue(MathHelper.NearEqual(roots[0], -2.0, 0.01));
Assert.IsTrue(MathHelper.NearEqual(roots[1], -1.0, 0.01));
Assert.IsTrue(MathHelper.NearEqual(roots[2], 1.0, 0.01));
}
public void TangentRoot()
{
Assert.IsTrue(MathHelper.NearEqual(RootFinder.TangentRoot(delegate(double x) { return(x * x - 1.0); },
delegate(double x) { return(2 * x); }, 2.0, 0.001), 1.0, 0.0011));
}
public void Bisection()
{
Assert.IsTrue(MathHelper.NearEqual(RootFinder.Bisection(delegate(double x)
{ return(x * x - 1.0); }, new Intervald(0.0, 10.0), 0.019), 1.0, 0.02));
}
