vec_math
Class Ellipse

java.lang.Object
  vec_math.Ellipse

public class Ellipse
extends Object

A tilted ellipse. Tilts by non-zero angles supported.

Field Summary

private double	a Ellipse is defined by it central point, major axis and excentricity.
private Point2D	center Ellipse is defined by it central point, major axis and excentricity.
private double	e Ellipse is defined by it central point, major axis and excentricity.
private double	theta Ellipse is defined by it central point, major axis and excentricity.

Constructor Summary

Ellipse()

Method Summary

private double	getBearing(Point2D p) We return the angle from the center to the stated point in degrees.
Point2D	getCenter()
double	getCentralRadius(double nu) Returns the radius of this ellipse as a function of the non-tilted angle ny.
private double	getCentralRadiusSq(double nu) Returns the square radius of this conic section as a function of the non-tilted angle ny.
double	getExcentricity() Returns the numerical excentricity.
double	getFocalRadius(double ny) Returns the radius of this conic section as a function of the non-tilted angle ny.
double	getMajorAxis()
double	getPerimeterDistance(Point2D p) Returns the distance of this point from the ellipse in radial direction.
private double	getPerimeterDistanceSq(Point2D p) Returns the distance of this point from the ellipse in radial direction.
Point2D	getPerimeterPoint(double phi) Returns the point at the given polar angle, counted from the center of the ellipse and corrected for ellipse tilt.
double	getTilt() Returns the tilt angle in degs.
boolean	isInside(Point2D p) We return true, if this point is within the ellipse.
static Ellipse	parseEllipse(String p) Parses the ellipse from a string.
void	setCenter(Point2D p) Sets the center of the ellipse.
void	setExcentricity(double eps) Sets the numerical excentricity.
void	setMajorAxis(double major) Sets the major axis.
void	setTilt(double t) Sets the tile angle in degs.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

center

private Point2D center

Ellipse is defined by it central point, major axis and excentricity.

a

private double a

Ellipse is defined by it central point, major axis and excentricity.

e

private double e

Ellipse is defined by it central point, major axis and excentricity.

theta

private double theta

Ellipse is defined by it central point, major axis and excentricity.

Constructor Detail

Ellipse

public Ellipse()

Method Detail

getFocalRadius

public double getFocalRadius(double ny)

Returns the radius of this conic section as a function of the non-tilted angle ny. Center is the focal point.

getCentralRadius

public double getCentralRadius(double nu)

Returns the radius of this ellipse as a function of the non-tilted angle ny. Center is the center of the ellipse.

getCentralRadiusSq

private double getCentralRadiusSq(double nu)

Returns the square radius of this conic section as a function of the non-tilted angle ny. Center is the center of the ellipse.

setTilt

public void setTilt(double t)

Sets the tile angle in degs.

getTilt

public double getTilt()

Returns the tilt angle in degs.

setCenter

public void setCenter(Point2D p)

Sets the center of the ellipse.

getCenter

public Point2D getCenter()

setMajorAxis

public void setMajorAxis(double major)

Sets the major axis.

getMajorAxis

public double getMajorAxis()

setExcentricity

public void setExcentricity(double eps)

Sets the numerical excentricity.

getExcentricity

public double getExcentricity()

Returns the numerical excentricity.

parseEllipse

public static Ellipse parseEllipse(String p)
                            throws ParseException

Parses the ellipse from a string. We follow the format of providing the center of the ellipse, followed by the major axis and the excentricity. The last item, if stated, is the tilt angle. All values are separated by commas, angles are in degrees.

Throws:

ParseException

isInside

public boolean isInside(Point2D p)

We return true, if this point is within the ellipse.

getBearing

private double getBearing(Point2D p)

We return the angle from the center to the stated point in degrees.

getPerimeterPoint

public Point2D getPerimeterPoint(double phi)

Returns the point at the given polar angle, counted from the center of the ellipse and corrected for ellipse tilt.

getPerimeterDistanceSq

private double getPerimeterDistanceSq(Point2D p)

Returns the distance of this point from the ellipse in radial direction. If the point is inside the ellipse, we return a negative value.

getPerimeterDistance

public double getPerimeterDistance(Point2D p)

Returns the distance of this point from the ellipse in radial direction. If the point is inside the ellipse, we return a negative value.

toString

public String toString()

Overrides:

toString in class Object