umontreal.iro.lecuyer.functions

Class ShiftedMathFunction

java.lang.Object

umontreal.iro.lecuyer.functions.ShiftedMathFunction

All Implemented Interfaces:

MathFunction, MathFunctionWithDerivative, MathFunctionWithFirstDerivative, MathFunctionWithIntegral

public class ShiftedMathFunction
extends java.lang.Object
implements MathFunction, MathFunctionWithFirstDerivative, MathFunctionWithDerivative, MathFunctionWithIntegral

Represents a function computing f (x) - δ for a user-defined function f (x) and shift δ.

Constructor Summary

Constructors

Constructor and Description
ShiftedMathFunction(MathFunction func, double delta) Constructs a new function shifting the function func by a shift delta.

Method Summary

Modifier and Type	Method and Description
double	derivative(double x) Computes (or estimates) the first derivative of the function at point x.
double	derivative(double x, int n) Computes (or estimates) the nth derivative of the function at point x.
double	evaluate(double x) Returns the value of the function evaluated at x.
double	getDelta() Returns the shift δ = delta.
MathFunction	getFunction() Returns the function f (x).
double	integral(double a, double b) Computes (or estimates) the integral of the function over the interval [a, b].

Methods inherited from class java.lang.Object

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

Constructor Detail

ShiftedMathFunction

public ShiftedMathFunction(MathFunction func,
                           double delta)

Constructs a new function shifting the function func by a shift delta.

Parameters:

func - the function.

delta - the shift.

Method Detail

getFunction

public MathFunction getFunction()

Returns the function f (x).

Returns:

the function.

getDelta

public double getDelta()

Returns the shift δ = delta.

Returns:

the shift.

evaluate

public double evaluate(double x)

Description copied from interface: MathFunction

Returns the value of the function evaluated at x.

Specified by:

evaluate in interface MathFunction

Parameters:

x - value at which the distribution function is evaluated

Returns:

function evaluated at x

derivative

public double derivative(double x)

Description copied from interface: MathFunctionWithFirstDerivative

Computes (or estimates) the first derivative of the function at point x.

Specified by:

derivative in interface MathFunctionWithFirstDerivative

Parameters:

x - the point to evaluate the derivative to.

Returns:

the value of the derivative.

derivative

public double derivative(double x,
                         int n)

Description copied from interface: MathFunctionWithDerivative

Computes (or estimates) the nth derivative of the function at point x. For n = 0, this returns the result of evaluate.

Specified by:

derivative in interface MathFunctionWithDerivative

Parameters:

x - the point to evaluate the derivate to.

n - the order of the derivative.

Returns:

the resulting derivative.

integral

public double integral(double a,
                       double b)

Description copied from interface: MathFunctionWithIntegral

Computes (or estimates) the integral of the function over the interval [a, b].

Specified by:

integral in interface MathFunctionWithIntegral

Parameters:

a - the starting point of the interval.

b - the ending point of the interval.

Returns:

the value of the integral.