com.luciad.projection

LuciadLightspeedClass TLcdEckertVI

java.lang.Object

com.luciad.projection.ALcdProjection

com.luciad.projection.ALcdCylindrical

com.luciad.projection.TLcdEckertVI

All Implemented Interfaces:

ILcdCylindrical, ILcdProjection, ILcdPropertyChangeSource, Serializable, Cloneable

public class TLcdEckertVI
extends ALcdCylindrical

Eckert VI projection.

Introduction

Pseudocylindrical equal-area projection with sinusoidal meridians.

Properties

• Pseudo-cylindrical projection, equal-area.
• The central meridian is a straight line.
• All other meridians are sinusoidal curves.
• Parallels are unequally spaced straight lines.
• Poles are straight lines half as long as the equator.
• Scale is true along latitudes 40°30' north and south.

Example

Sample code

 ILcdProjection projection =
     new TLcdEckertVI(0.0);
 

Implementation aspects

The equations of the Eckert VI projection are taken from [Snyder1987].

Since:

V 3.0

See Also:

Serialized Form

Field Summary

Fields inherited from class com.luciad.projection.ALcdProjection

fPropertyChangeDispatcher

Fields inherited from interface com.luciad.projection.ILcdProjection

EPSILON

Constructor Summary

Constructors

Constructor and Description
TLcdEckertVI() Constructs a Eckert VI projection with the central meridian at 0.
TLcdEckertVI(double aCentralMeridian) Constructs a Eckert VI projection with a given central meridian.

Method Summary

Modifier and Type	Method and Description
double[][]	boundaryLats(double aLongitude) Default implementation.
double[][]	boundaryLons(double aLatitude) Default implementation.
boolean	inLonLatBounds(ILcdPoint aLLHP) Checks if an ILcdPoint is inside the valid area of geodetic coordinates of the projection.
boolean	inWorldBoundsOnSphere(ILcdPoint aXYPoint, double aRadius) Checks if a ILcdPoint is inside the valid cartesian area of the projection.
boolean	isAllInBounds() If all geodetic coordinates (l ,j ) are projected (visible) by an ILcdProjection and all (x,y ) coordinates are bounded this is true.
void	lonlatheight2worldOnSphereSFCT(ILcdPoint aLLHP, double aRadius, ILcd2DEditablePoint aXYPointSFCT) Transforms an ILcd2DEditablePoint on a sphere into the cartesian coordinate system of the projection.
String	toString() Returns the String representation of the Eckert VI projection.
void	world2DEditableBoundsOnSphereSFCT(double aRadius, ILcd2DEditableBounds aWorldBounds) Sets the ILcd2DEditableBounds object to the bounds of the projection in world coordinates.
void	world2lonlatOnSphereSFCT(ILcdPoint aXYPoint, double aRadius, ILcd2DEditablePoint aLLPointSFCT) Transforms an ILcdPoint from the cartesian coordinate system of the projection into an ILcd2DEditablePoint onto a sphere.

Methods inherited from class com.luciad.projection.ALcdCylindrical

calculateCachedValues, clone, equals, getCentralMeridian, getOrigin, hashCode, isContinuous, loadProperties, setCentralMeridian, writePropertiesSFCT

Methods inherited from class com.luciad.projection.ALcdProjection

addPropertyChangeListener, firePropertyChangeEvent, inWorldBoundsOnEllipsoid, lonlatheight2worldOnEllipsoidSFCT, removePropertyChangeListener, world2DEditableBoundsOnEllipsoidSFCT, world2lonlatOnEllipsoidSFCT

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.luciad.projection.ILcdProjection

inWorldBoundsOnEllipsoid, lonlatheight2worldOnEllipsoidSFCT, world2DEditableBoundsOnEllipsoidSFCT, world2lonlatOnEllipsoidSFCT

Methods inherited from interface com.luciad.util.ILcdPropertyChangeSource

addPropertyChangeListener, removePropertyChangeListener

Constructor Detail

TLcdEckertVI

public TLcdEckertVI()

Constructs a Eckert VI projection with the central meridian at 0.

TLcdEckertVI

public TLcdEckertVI(double aCentralMeridian)

Constructs a Eckert VI projection with a given central meridian.

Parameters:

aCentralMeridian - the central meridian for the Eckert VI projection.

Method Detail

isAllInBounds

public boolean isAllInBounds()

Description copied from interface: ILcdProjection

If all geodetic coordinates (l ,j ) are projected (visible) by an ILcdProjection and all (x,y ) coordinates are bounded this is true. All ILcdProjection objects have bounded (x,y ) coordinates because the projection is cut off if necessary.

Returns:

true if all LonLatPoints are within the bounds of the projection, false otherwise.

lonlatheight2worldOnSphereSFCT

public void lonlatheight2worldOnSphereSFCT(ILcdPoint aLLHP,
                                           double aRadius,
                                           ILcd2DEditablePoint aXYPointSFCT)
                                    throws TLcdOutOfBoundsException

Description copied from interface: ILcdProjection

Transforms an ILcd2DEditablePoint on a sphere into the cartesian coordinate system of the projection.

Parameters:

aLLHP - point to be projected.

aRadius - radius of the sphere (meters).

aXYPointSFCT - projected point as side effect.

Throws:

TLcdOutOfBoundsException - If the ILcdPoint aLLHP is not within the valid area of the projection (visible area), then this exception is thrown.

world2lonlatOnSphereSFCT

public void world2lonlatOnSphereSFCT(ILcdPoint aXYPoint,
                                     double aRadius,
                                     ILcd2DEditablePoint aLLPointSFCT)
                              throws TLcdOutOfBoundsException

Description copied from interface: ILcdProjection

Transforms an ILcdPoint from the cartesian coordinate system of the projection into an ILcd2DEditablePoint onto a sphere.

Parameters:

aXYPoint - projected point for which the corresponding geodetic point is sought.

aRadius - radius of the sphere (meters).

aLLPointSFCT - resulting geodetic coordinate as side effect.

Throws:

TLcdOutOfBoundsException - If the ILcdPoint aXYPoint is not within the valid area of the projection (visible area), then this exception is thrown.

inLonLatBounds

public boolean inLonLatBounds(ILcdPoint aLLHP)

Description copied from interface: ILcdProjection

Checks if an ILcdPoint is inside the valid area of geodetic coordinates of the projection. The valid area is determined by the LonLatPoints that are visible and for which the corresponding cartesian coordinate is within the boundaries.

Parameters:

aLLHP - ILcdPoint to be checked upon.

Returns:

true if valid, false if invalid.

inWorldBoundsOnSphere

public boolean inWorldBoundsOnSphere(ILcdPoint aXYPoint,
                                     double aRadius)

Description copied from interface: ILcdProjection

Checks if a ILcdPoint is inside the valid cartesian area of the projection. The valid cartesian area is determined naturally by the projection bounds or by an artificial introduced boundary limit because some cartesian points are at infinity. The shape of the valid cartesian area is in many cases rectangular or circular although it might be more complex.

Parameters:

aXYPoint - point to be checked upon.

aRadius - radius of the sphere.

Returns:

true if valid, false if invalid.

world2DEditableBoundsOnSphereSFCT

public void world2DEditableBoundsOnSphereSFCT(double aRadius,
                                              ILcd2DEditableBounds aWorldBounds)

Description copied from interface: ILcdProjection

Sets the ILcd2DEditableBounds object to the bounds of the projection in world coordinates.

Parameters:

aRadius - radius of the sphere.

aWorldBounds - the bounds of the projection in world coordinates as side effect.

boundaryLons

public double[][] boundaryLons(double aLatitude)

Description copied from class: ALcdProjection

Default implementation. To be redefined for specific projections.

Specified by:

boundaryLons in interface ILcdProjection

Overrides:

boundaryLons in class ALcdProjection

Parameters:

aLatitude - latitude in decimal degrees and -90.0 <= aLat<= 90.0.

Returns:

the array of pairs of longitudes[0] and longitudes[1], where the closed interval longitudes[0] -> longitudes[1] is in visible area and -180.0 <= lon[i] <= 180.0.

boundaryLats

public double[][] boundaryLats(double aLongitude)

Description copied from class: ALcdProjection

Default implementation. To be redefined for specific projections.

Specified by:

boundaryLats in interface ILcdProjection

Overrides:

boundaryLats in class ALcdProjection

Parameters:

aLongitude - longitude in decimal degrees -180.0 <= lon <= 180.0 .

Returns:

the array of pairs of latitudes lats[0] and lats[1], where the closed interval lats[0] -> lats[1] is in visible area and -90.0 <= lats[i] <= 90.0 .

toString

public String toString()

Returns the String representation of the Eckert VI projection.

Specified by:

toString in interface ILcdProjection

Overrides:

toString in class Object

Returns:

the String representation of the Eckert VI projection.