org.josef.science.math

Class FunctionInterval

java.lang.Object

org.josef.science.math.FunctionInterval

@Status(stage=PRODUCTION,
        unitTests=COMPLETE)
 @Review(by="Kees Schotanus",
        at="2011-12-16",
        reason="Initial review")
 @ThreadSafety(level=NOT_THREAD_SAFE)
public final class FunctionInterval
extends Object

Abstraction of an interval of a function. An interval is described by a function and x values for both the left and the right side of the interval.

Version:

1.0 $Revision: 6488 $

Author:

Kees Schotanus

Constructor Summary

Constructors

Constructor and Description
FunctionInterval(SingleParameterFunction function, double left, double right) Creates this FunctionInterval from the supplied function and left and right sides of the interval.

Method Summary

Modifier and Type	Method and Description
double	a() Gets the left side of this interval.
double	b() Gets the right side of this interval.
double	c() Gets the point between a and b.
void	checkForRoot() Checks this interval for having a possible root so this interval can be used by a root finding method like the Bisection method or the RegulaFalsi method.
double	fa() Gets f(a).
double	fb() Gets f(b).
double	fc() Gets f(c).
void	setA(double a) Sets the left side for this interval.
void	setB(double b) Sets the right side for this interval.
void	setC(double c) Sets a value c between a and calculates f(c).
void	setFa(double fa) Sets f(a).
void	setFb(double fb) Sets f(b).

Methods inherited from class java.lang.Object

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

Constructor Detail

FunctionInterval

public FunctionInterval(SingleParameterFunction function,
                        double left,
                        double right)

Creates this FunctionInterval from the supplied function and left and right sides of the interval.

Parameters:

function - The function corresponding to this interval.

left - The left side of the interval.

right - The right side of the interval.

Throws:

NullPointerException - When the supplied function is null.

Method Detail

checkForRoot

public void checkForRoot()

Checks this interval for having a possible root so this interval can be used by a root finding method like the Bisection method or the RegulaFalsi method.
This method checks that

• a unequal to b
• fa and fb are actual numbers (not NaN)
• fa and fb have opposite signs

Throws:

IllegalArgumentException - When this interval does not represent an interval as described by the rules above.

a

public double a()

Gets the left side of this interval.

Returns:

The left side of this interval.

setA

public void setA(double a)

Sets the left side for this interval.

Parameters:

a - The left side of this interval.

fa

public double fa()

Gets f(a).

Returns:

f(a).

setFa

public void setFa(double fa)

Sets f(a).

Parameters:

fa - f(a).

b

public double b()

Gets the right side of this interval.

Returns:

The right side of this interval.

setB

public void setB(double b)

Sets the right side for this interval.

Parameters:

b - The right side of this interval.

fb

public double fb()

Gets f(b).

Returns:

f(b).

setFb

public void setFb(double fb)

Sets f(b).

Parameters:

fb - f(b).

c

public double c()

Gets the point between a and b.

Returns:

The point between a and b.

fc

public double fc()

Gets f(c).

Returns:

f(c).

setC

public void setC(double c)

Sets a value c between a and calculates f(c).

Parameters:

c - A value between a and b. Note: No check is made whether c is actually between a and b.