FunctionMath.BackwardDerivative(Func<Double, Double>, Double, Double, Int32) Method

Returns an approximation to the derivative of a function by using only function values at x and and values smaller than x.

Definition

Namespace: Extreme.Mathematics
Assembly: Extreme.Numerics (in Extreme.Numerics.dll) Version: 8.1.23

public static double BackwardDerivative(
	this Func<double, double> targetFunction,
	double x,
	out double estimatedError,
	out int evaluationsNeeded
)

Visual Basic

<ExtensionAttribute>
Public Shared Function BackwardDerivative ( 
	targetFunction As Func(Of Double, Double),
	x As Double,
	<OutAttribute> ByRef estimatedError As Double,
	<OutAttribute> ByRef evaluationsNeeded As Integer
) As Double

C++/CLI

public:
[ExtensionAttribute]
static double BackwardDerivative(
	Func<double, double>^ targetFunction, 
	double x, 
	[OutAttribute] double% estimatedError, 
	[OutAttribute] int% evaluationsNeeded
)

[<ExtensionAttribute>]
static member BackwardDerivative : 
        targetFunction : Func<float, float> * 
        x : float * 
        estimatedError : float byref * 
        evaluationsNeeded : int byref -> float

Parameters

targetFunction Func<Double, Double>: A delegate that represents a function of one variable that specifies the function to differentiate.
x Double: The point at which to evaluate the derivative.
estimatedError Double: On exit, this parameter contains an estimate of the absolute error of the approximation.
evaluationsNeeded Int32: On exit, this parameter contains the number of function evaluations needed to calculate the numerical derivative.

Return Value

Double
A numerical approximation to the derivative of targetFunction at x.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type Func<Double, Double>. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Exceptions

ArgumentNullException

targetFunction is null.