public virtual double Laguerre(double lo, double hi, double fLo, double fHi)
{
Complex[] c = ComplexUtils.convertToComplex(Coefficients);
Complex initial = new Complex(0.5 * (lo + hi), 0);
Complex z = ComplexSolver.Solve(c, initial);
if (ComplexSolver.IsRoot(lo, hi, z))
{
return z.Real;
}
else
{
double r = double.NaN;
// Solve all roots and select the one we are seeking.
Complex[] root = ComplexSolver.SolveAll(c, initial);
for (int i = 0; i < root.Length; i++)
{
if (ComplexSolver.IsRoot(lo, hi, root[i]))
{
r = root[i].Real;
break;
}
}
return r;
}
}
/// <summary>
/// Find all complex roots for the polynomial with the given
/// coefficients, starting from the given initial value.
/// <br/>
/// Note: This method is not part of the API of <seealso cref="BaseUnivariateSolver"/>.
/// </summary>
/// <param name="coefficients"> Polynomial coefficients. </param>
/// <param name="initial"> Start value. </param>
/// <returns> the point at which the function value is zero. </returns>
/// <exception cref="org.apache.commons.math3.exception.TooManyEvaluationsException">
/// if the maximum number of evaluations is exceeded. </exception>
/// <exception cref="NullArgumentException"> if the {@code coefficients} is
/// {@code null}. </exception>
/// <exception cref="NoDataException"> if the {@code coefficients} array is empty.
/// @since 3.1 </exception>
public virtual Complex[] SolveAllComplex(double[] coefficients, double initial)
{
Setup(int.MaxValue, new PolynomialFunction(coefficients), double.NegativeInfinity, double.PositiveInfinity, initial);
return ComplexSolver.SolveAll(ComplexUtils.convertToComplex(coefficients), new Complex(initial, 0d));
}