static bool TryScanForCrossingsWithRoots(Func <double, double> f, Func <double, double> df, double lowerBound, double upperBound, double accuracy, int maxIterations, int subdivision, out double root)
{
var zeroCrossings = ZeroCrossingBracketing.FindIntervalsWithin(f, lowerBound, upperBound, subdivision);
foreach (Tuple <double, double> bounds in zeroCrossings)
{
if (TryFindRoot(f, df, bounds.Item1, bounds.Item2, accuracy, maxIterations, subdivision, out root))
{
return(true);
}
}
root = double.NaN;
return(false);
}
/// <summary>Find a solution of the equation f(x)=0.</summary>
/// <param name="f">The function to find roots from.</param>
/// <param name="guessLowerBound">Guess for the low value of the range where the root is supposed to be. Will be expanded if needed.</param>
/// <param name="guessUpperBound">Guess for the high value of the range where the root is supposed to be. Will be expanded if needed.</param>
/// <param name="accuracy">Desired accuracy. The root will be refined until the accuracy or the maximum number of iterations is reached. Default 1e-8.</param>
/// <param name="maxIterations">Maximum number of iterations. Default 100.</param>
/// <param name="expandFactor">Factor at which to expand the bounds, if needed. Default 1.6.</param>
/// <param name="maxExpandIteratons">Maximum number of expand iterations. Default 100.</param>
/// <returns>Returns the root with the specified accuracy.</returns>
/// <exception cref="NonConvergenceException"></exception>
public static double FindRootExpand(Func <double, double> f, double guessLowerBound, double guessUpperBound, double accuracy = 1e-8, int maxIterations = 100, double expandFactor = 1.6, int maxExpandIteratons = 100)
{
ZeroCrossingBracketing.ExpandReduce(f, ref guessLowerBound, ref guessUpperBound, expandFactor, maxExpandIteratons, maxExpandIteratons * 10);
return(FindRoot(f, guessLowerBound, guessUpperBound, accuracy, maxIterations));
}