public static double Solve(Func <double, double> f, double min, double max, Type solverType, double absoluteAccuracy, int maxEval)
{
UnivariateSolver solver;
switch (solverType)
{
case Type.BrentSolver:
{
solver = new BrentSolver(absoluteAccuracy);
break;
}
case Type.BisectionSolver:
{
solver = new BisectionSolver(absoluteAccuracy);
break;
}
case Type.SecantSolver:
{
solver = new SecantSolver(absoluteAccuracy);
break;
}
default:
{
throw new IndexOutOfRangeException();
}
}
double v = solver.Solve(maxEval, new DelegateUnivariateFunction(f), min, max);
return(v);
}
private static UnivariateSolver GetSolver(Type type, double error = DEFAULT_ABSOLUTE_ACCURACY)
{
UnivariateSolver univariateSolver;
switch (type)
{
case Type.Brent:
univariateSolver = new BrentSolver(error);
break;
case Type.Bisection:
univariateSolver = new BisectionSolver(error);
break;
case Type.Secant:
univariateSolver = new SecantSolver(error);
break;
case Type.RegulaFalsi:
univariateSolver = new RegulaFalsiSolver(error);
break;
case Type.Ridders:
univariateSolver = new RiddersSolver(error);
break;
default:
throw new IndexOutOfRangeException();
}
return(univariateSolver);
}
public void FindRoot_CosFunction_ReturnsRootWithinTolerance()
{
OneDimensionalFunction f = Math.Cos;
double lowerBound = -Math.PI / 2;
double upperBound = Math.PI;
BisectionSolver solver = new BisectionSolver(f, lowerBound, upperBound);
var root = solver.FindRoot();
Assert.IsTrue(Math.Abs(f(root)) < solver.Tolerance);
}
public void FindRoot_QuadraticIncorrectIntialGuess_ReturnsRootWithinTolerance()
{
OneDimensionalFunction f = x => x * x - 4;
double lowerBound = -1;
double upperBound = 3;
BisectionSolver solver = new BisectionSolver(f, lowerBound, upperBound);
var root = solver.FindRoot();
Assert.IsTrue(Math.Abs(f(root)) < solver.Tolerance);
}
public void FindRoot_PolynomialLowerBoundIsZero_ReturnsExactRoot()
{
OneDimensionalFunction f = x => x * x - 4;
double lowerBound = -2;
double upperBound = 3;
BisectionSolver solver = new BisectionSolver(f, lowerBound, upperBound);
var root = solver.FindRoot();
Assert.AreEqual(lowerBound, root);
}
