public GetParameterHelper1F()
{
_rootFinder = new ImprovedNewtonRaphsonMethodF(GetPoint, GetTangent);
}
public GetParameterHelper3F()
{
_rootFinder = new ImprovedNewtonRaphsonMethodF(GetLength, GetTangentLength);
}
// This method shows how to use root finding.
// A method y = Foo(x) is given and we want to find x such that Foo(x) = 7.
private void FindRoot()
{
var debugRenderer = GraphicsScreen.DebugRenderer2D;
debugRenderer.DrawText("----- RootFinding Example:");
// Create a new instance of a root finder class.
// The Newton-Raphson root finding method uses the function and the first-order
// derivative of the function where we want to find solutions. If the derivate
// is not known, other root finding classes can be used, like the BisectionMethod
// or RegulaFalsiMethod classes.
var rootFinder = new ImprovedNewtonRaphsonMethodF(Foo, FooDerived);
// Several x could result in Foo(x) = 7. So we need to define an x interval
// that contains the desired x solution.
// We decide to look for a solution near x = 0 and let the rootFinder approximate
// an x interval that contains the result.
float x0 = 0;
float x1 = 0;
// Find an interval [x0, x1] that contains an x such that Foo(x) = 7.
rootFinder.ExpandBracket(ref x0, ref x1, 7);
// Now we use the root finder to find an x within [x0, x1] such that Foo(x) = 7.
float x = rootFinder.FindRoot(x0, x1, 7);
// Lets check the result.
float y = Foo(x);
// Important note: We use Numeric.AreEqual() to safely compare floating-point numbers.
if (Numeric.AreEqual(y, 7))
debugRenderer.DrawText("Solution is correct.\n");
else
debugRenderer.DrawText("Solution is wrong.\n");
}
