com.numericalmethod.suanshu.analysis.differentiation.univariate
Class Dfdx

java.lang.Object
  com.numericalmethod.suanshu.analysis.function.rn2r1.UnivariateRealFunction
      com.numericalmethod.suanshu.analysis.differentiation.univariate.Dfdx

All Implemented Interfaces:

Function, RealScalarFunction

public class Dfdx
extends UnivariateRealFunction

This class computes the first order derivative function of a univariate function.

The first derivative is a measure of how a function changes as its input changes. In other words, a derivative is how much a quantity changes if the input changes (by a very small amount). The derivative of a function at a particular point is the best linear approximation of the function at that point. For a univariate real function, the derivative at a point is the slope of the tangent line to the function at that point.

See Also:

Wikipedia: Derivative

Nested Class Summary

static class

Dfdx.Method the methods available to compute numerical derivatives

Nested classes/interfaces inherited from interface com.numericalmethod.suanshu.analysis.function.Function

Function.EvaluationException

Constructor Summary

Dfdx(UnivariateRealFunction f)
Construct, using finite difference, the first order derivative function of a univariate function f.

Dfdx(UnivariateRealFunction f, Dfdx.Method method)
Construct the first order derivative function of a univariate function f.

Method Summary

double

evaluate(double x) Evaluate f'(x).

Methods inherited from class com.numericalmethod.suanshu.analysis.function.rn2r1.UnivariateRealFunction

dimension4Domain, dimension4Range, evaluate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Dfdx

public Dfdx(UnivariateRealFunction f,
            Dfdx.Method method)

Construct the first order derivative function of a univariate function f.

Parameters:

f - a univariate function

method - the numerical method to use, c.f., Dfdx.Method

Dfdx

public Dfdx(UnivariateRealFunction f)

Construct, using finite difference, the first order derivative function of a univariate function f.

Parameters:

f - a univariate function

Method Detail

evaluate

public double evaluate(double x)

Evaluate f'(x).

Specified by:

evaluate in class UnivariateRealFunction

Parameters:

x - x

Returns:

f'(x)