ilog.views.maps.projection
Class IlvEllipsoid

java.lang.Object
  ilog.views.maps.projection.IlvEllipsoid

All Implemented Interfaces:

IlvPersistentObject, Serializable

public class IlvEllipsoid
extends Object
implements Serializable, IlvPersistentObject

This class defines an ellipsoid. Ellipsoids are used in map projections to represent the figure of the earth. For many applications, and especially in small-scale mapping, the earth can be represented as a sphere. However, because the earth rotates on its axis and is slightly flattened, it is better approximated by an ellipsoid of rotation about the polar axis. Ellipsoidal projections are used for accurate large-scale maps and plane coordinate systems.

See Also:

Serialized Form

Field Summary

static IlvEllipsoid	CPM The ellipsoid specified by the French Weights and Measures Commission ("Commission des Poids et Mesures") in 1799.
static IlvEllipsoid	SGS85 The ellipsoid used in the Soviet Geodetic System 85
static IlvEllipsoid	SPHERE A spherical ellipsoid representing the earth.
static IlvEllipsoid	WGS60 The WGS 60 ellipsoid.
static IlvEllipsoid	WGS66 The WGS 66 ellipsoid.
static IlvEllipsoid	WGS72 The WGS 72 ellipsoid.
static IlvEllipsoid	WGS84 The WGS 84 ellipsoid.

Constructor Summary

IlvEllipsoid(double radius)
Creates a sphere with the specified radius.

IlvEllipsoid(double a, double es)
Creates an ellipsoid with the specified equatorial radius and eccentricity.

IlvEllipsoid(double a, double es, String name, String comment)
Creates a named ellipsoid with the specified equatorial radius and eccentricity.

IlvEllipsoid(IlvInputStream stream)
Reads the object from an IlvInputStream.

Method Summary

boolean	equivalent(IlvEllipsoid e) Returns true if the ellipsoid passed as the argument is equivalent to the object.
static double	ESFromFlattening(double f) Returns the eccentricity squared which is computed from the flattening of the ellipsoid.
static double	ESFromPolarRadius(double a, double b) Returns the eccentricity squared which is computed from the semi-major axis and the semi-minor axis of the ellipsoid.
double	getA() Returns the semi-major axis of the ellipsoid.
IlvEllipsoid	getASphere() Returns a sphere whose radius is the arithmetic mean of the minor and major axes.
IlvEllipsoid	getASphere(double phi) Returns a sphere whose radius is the arithmetic mean of the principle radii at the specified latitude.
double	getB() Returns the semi-minor axis of the ellipsoid.
String	getComment() Returns a description of the ellipsoid, if available.
double	getES() Returns the eccentricity squared of the ellipsoid.
IlvEllipsoid	getGSphere() Returns a sphere whose radius is the geometric mean of the minor and major axes.
IlvEllipsoid	getGSphere(double phi) Returns a sphere whose radius is the geometric mean of the principle radii at the specified latitude.
IlvEllipsoid	getHSphere() Returns a sphere whose radius is the harmonic mean of the minor and major axes.
String	getName() Returns the name of the ellipsoid.
IlvEllipsoid	getSphereOfSameArea() Returns a sphere of equivalent surface area.
IlvEllipsoid	getSphereOfSameVolume() Returns a sphere of equivalent volume.
boolean	isSphere() Returns true if the ellipsoid is a sphere.
String	toString() Converts the ellipsoid to a string.
void	write(IlvOutputStream stream) Writes the object onto an IlvOutputStream.

Methods inherited from class java.lang.Object

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

Field Detail

SPHERE

public static final IlvEllipsoid SPHERE

A spherical ellipsoid representing the earth.

See Also:

IlvEllipsoidCollection.getEllipsoids()

SGS85

public static final IlvEllipsoid SGS85

The ellipsoid used in the Soviet Geodetic System 85

See Also:

IlvEllipsoidCollection.getEllipsoids()

CPM

public static final IlvEllipsoid CPM

The ellipsoid specified by the French Weights and Measures Commission ("Commission des Poids et Mesures") in 1799.

See Also:

IlvEllipsoidCollection.getEllipsoids()

WGS60

public static final IlvEllipsoid WGS60

The WGS 60 ellipsoid.

See Also:

IlvEllipsoidCollection.getEllipsoids()

WGS66

public static final IlvEllipsoid WGS66

The WGS 66 ellipsoid.

See Also:

IlvEllipsoidCollection.getEllipsoids()

WGS72

public static final IlvEllipsoid WGS72

The WGS 72 ellipsoid.

See Also:

IlvEllipsoidCollection.getEllipsoids()

WGS84

public static final IlvEllipsoid WGS84

The WGS 84 ellipsoid.

See Also:

IlvEllipsoidCollection.getEllipsoids()

Constructor Detail

IlvEllipsoid

public IlvEllipsoid(double radius)

Creates a sphere with the specified radius.

Parameters:

radius - the radius of the sphere in meters

IlvEllipsoid

public IlvEllipsoid(double a,
                    double es)

Creates an ellipsoid with the specified equatorial radius and eccentricity.

Parameters:

a - semi-major axis of the ellipsoid or equatorial radius

es - eccentricity squared of the ellipsoid

IlvEllipsoid

public IlvEllipsoid(double a,
                    double es,
                    String name,
                    String comment)

Creates a named ellipsoid with the specified equatorial radius and eccentricity.

Parameters:

a - semi-major axis of the ellipsoid or equatorial radius

es - eccentricity squared of the ellipsoid

name - name of the ellipsoid

comment - a short comment describing the ellipsoid

IlvEllipsoid

public IlvEllipsoid(IlvInputStream stream)
             throws IlvReadFileException

Reads the object from an IlvInputStream.

Parameters:

stream - the input stream.

Throws:

IlvReadFileException - if the format is not correct.

Since:

JViews 3.0

Method Detail

getA

public final double getA()

Returns the semi-major axis of the ellipsoid.

getB

public final double getB()

Returns the semi-minor axis of the ellipsoid.

getES

public final double getES()

Returns the eccentricity squared of the ellipsoid.

isSphere

public boolean isSphere()

Returns true if the ellipsoid is a sphere.

getSphereOfSameArea

public IlvEllipsoid getSphereOfSameArea()

Returns a sphere of equivalent surface area.

getSphereOfSameVolume

public IlvEllipsoid getSphereOfSameVolume()

Returns a sphere of equivalent volume.

getASphere

public IlvEllipsoid getASphere()

Returns a sphere whose radius is the arithmetic mean of the minor and major axes.

getASphere

public IlvEllipsoid getASphere(double phi)

Returns a sphere whose radius is the arithmetic mean of the principle radii at the specified latitude.

Parameters:

phi - the latitude in radians

See Also:

IlvProjectionUtil.DMSToRadian(java.lang.String), IlvProjectionUtil.DegreeToRadian(double)

getGSphere

public IlvEllipsoid getGSphere()

Returns a sphere whose radius is the geometric mean of the minor and major axes.

getGSphere

public IlvEllipsoid getGSphere(double phi)

Returns a sphere whose radius is the geometric mean of the principle radii at the specified latitude.

Parameters:

phi - the latitude in radians.

See Also:

IlvProjectionUtil.DMSToRadian(java.lang.String), IlvProjectionUtil.DegreeToRadian(double)

getHSphere

public IlvEllipsoid getHSphere()

Returns a sphere whose radius is the harmonic mean of the minor and major axes.

ESFromPolarRadius

public static double ESFromPolarRadius(double a,
                                       double b)

Returns the eccentricity squared which is computed from the semi-major axis and the semi-minor axis of the ellipsoid.

Parameters:

a - semi-major axis of the ellipsoid or equatorial radius.

b - semi-minor axis of the ellipsoid or polar radius.

ESFromFlattening

public static double ESFromFlattening(double f)

Returns the eccentricity squared which is computed from the flattening of the ellipsoid.

Parameters:

f - flattening of the ellipsoid.

getName

public String getName()

Returns the name of the ellipsoid.

getComment

public String getComment()

Returns a description of the ellipsoid, if available.

write

public void write(IlvOutputStream stream)
           throws IOException

Writes the object onto an IlvOutputStream.

Specified by:

write in interface IlvPersistentObject

Parameters:

stream - the output stream

Throws:

IOException - thrown when an exception occurs during the write operation for this object.

Since:

JViews 3.0

equivalent

public boolean equivalent(IlvEllipsoid e)

Returns true if the ellipsoid passed as the argument is equivalent to the object.

Since:

JViews 3.0

toString

public String toString()

Converts the ellipsoid to a string.

Overrides:

toString in class Object