org.arp.javautil.stat

Class Line

java.lang.Object

org.arp.javautil.stat.Line

public class Line
extends Object

A class for manipulating lines in a cartesian plane. Lines may be expressed by the formula y = mx + b, where m is the slope, b is the y-intercept, and y and x are coordinates in the cartesian plane. Java's floating point arithmetic has built-in support for infinite values as defined by the IEEE 754 standard. Special methods are used to test for this condition. See the API documentation for class Double for details.

Author:

Andrew Post

Field Summary

Fields

Modifier and Type	Field and Description
protected double	b
protected double	m

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Line() Creates new Line for subclasses only.
	Line(double m, double b) Creates new Line.

Method Summary

Modifier and Type	Method and Description
double	getb() Returns the y-intercept of this line.
double	getm() Returns the slope of this line.
double	getx(double y) Returns the value of x given y.
double	gety(double x) Returns the value of y given x.
protected void	setb(double b) Sets the value of the intercept for this line.
protected void	setm(double m) Sets the value of the slope for this line.

Methods inherited from class java.lang.Object

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

Field Detail

m

protected double m

b

protected double b

Constructor Detail

Line

public Line(double m,
            double b)

Creates new Line.

Parameters:

m - the slope.

b - the y-intercept.

Line

protected Line()

Creates new Line for subclasses only. Subclass writers must define m and b with the setm() and setb() manually if they don't use the above constructor. The default values for the slope and intercept are both 0.0.

Method Detail

setm

protected void setm(double m)

Sets the value of the slope for this line.

Parameters:

m - the new slope.

setb

protected void setb(double b)

Sets the value of the intercept for this line.

Parameters:

b - the new intercept.

getm

public double getm()

Returns the slope of this line. If you're concerned that the slope might be positive or negative infinity, use Double.isInfinite() and Double.isNaN() to find out.

Returns:

the slope of this line.

getb

public double getb()

Returns the y-intercept of this line. If you're concerned that the intercept might be positive or negative infinity, use Double.isInfinite() and Double.isNaN() to find out.

Returns:

the y-intercept of this line.

getx

public double getx(double y)

Returns the value of x given y. If you're concerned that the value of x may be infinite, use Double.isInfinite() and Double.isNaN() to find out.

Parameters:

y - a value for y along this line.

Returns:

the value of x given y.

gety

public double gety(double x)

Returns the value of y given x. If you're concerned that the value of y may be infinite, use Double.isInfinite() and Double.isNaN() to find out.

Parameters:

x - a value for x along this line.

Returns:

the value of y given x.