com.bbn.openmap.proj.coords
Class LatLonPoint

java.lang.Object
  java.awt.geom.Point2D
      com.bbn.openmap.proj.coords.LatLonPoint

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

Direct Known Subclasses:

LatLonPoint.Double, LatLonPoint.Float

public abstract class LatLonPoint
extends java.awt.geom.Point2D
implements java.lang.Cloneable, java.io.Serializable

A Point2D representation of LatLonPoints, used integrate with the Projections. These LatLonPoints wrap their internal decimal degree values so the latitude are between -90 and 90 and the longitudes are between -180 and 180. Radian values are precalculated and held within the object.

The LatLonPoint is an abstract class and can't be instantiated directly. You need to create a Float or Double version of a LatLonPoint, much like the Point2D object.

Author:

dietrick

See Also:

Serialized Form

Nested Class Summary

static class	LatLonPoint.Double Double precision version of LatLonPoint.
static class	LatLonPoint.Float The Float version of a LatLonPoint, where coordinates are held to float precision.

Field Summary

static double	DATELINE
static double	LON_RANGE
static double	NORTH_POLE
static double	SOUTH_POLE

Constructor Summary

protected

LatLonPoint()

Method Summary

double	azimuth(LatLonPoint toPoint) Find the azimuth to another point, based on the spherical earth model.
double	distance(LatLonPoint toPoint) Find the distance to another LatLonPoint, based on a earth spherical model.
boolean	equals(java.lang.Object obj) Determines whether two LatLonPoints are equal.
static LatLonPoint	getDouble(java.awt.geom.Point2D pt2D) Factory method that will create a LatLonPoint.Double from a Point2D object.
static LatLonPoint	getFloat(java.awt.geom.Point2D pt2D) Factory method that will create a LatLonPoint.Float from a Point2D object.
abstract float	getLatitude()
abstract float	getLongitude()
LatLonPoint	getPoint(double distance, double azimuth) Get a new LatLonPoint a distance and azimuth from another point, based on the spherical earth model.
abstract double	getRadLat()
abstract double	getRadLon()
static boolean	isInvalidLatitude(double lat) Check if latitude is bogus.
static boolean	isInvalidLongitude(double lon) Check if longitude is bogus.
static double	normalizeLatitude(double lat) Sets latitude to something sane.
static float	normalizeLatitude(float lat) Ensure latitude is between the poles.
abstract void	setLatitude(double lat) Set decimal degree latitude.
abstract void	setLatLon(double lat, double lon) Set the latitude, longitude for this point.
abstract void	setLatLon(double lat, double lon, boolean isRadians) Set the latitude, longitude for this point, with the option of noting whether the values are in degrees or radians.
void	setLatLon(LatLonPoint llp) Set location values from another lat/lon point.
abstract void	setLongitude(double lon) Set decimal degree longitude.
static double	wrapLongitude(double lon) Sets longitude to something sane.
static float	wrapLongitude(float lon) Ensure the longitude is between the date line.

Methods inherited from class java.awt.geom.Point2D

clone, distance, distance, distance, distanceSq, distanceSq, distanceSq, getX, getY, hashCode, setLocation, setLocation

Methods inherited from class java.lang.Object

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

Field Detail

NORTH_POLE

public static final double NORTH_POLE

See Also:

Constant Field Values

SOUTH_POLE

public static final double SOUTH_POLE

See Also:

Constant Field Values

DATELINE

public static final double DATELINE

See Also:

Constant Field Values

LON_RANGE

public static final double LON_RANGE

See Also:

Constant Field Values

Constructor Detail

LatLonPoint

protected LatLonPoint()

Method Detail

getFloat

public static LatLonPoint getFloat(java.awt.geom.Point2D pt2D)

Factory method that will create a LatLonPoint.Float from a Point2D object. If pt2D is already a LatLonPoint.Float object, it is simply returned.

Parameters:

pt2D -

Returns:

a LatLonPoint.Float object.

getDouble

public static LatLonPoint getDouble(java.awt.geom.Point2D pt2D)

Factory method that will create a LatLonPoint.Double from a Point2D object. If pt2D is already a LatLonPoint.Double object, it is simply returned.

Parameters:

pt2D -

Returns:

a LatLonPoint.Double object.

setLatLon

public abstract void setLatLon(double lat,
                               double lon)

Set the latitude, longitude for this point.

Parameters:

lat - decimal degree latitude

lon - decimal degree longitude.

setLatLon

public abstract void setLatLon(double lat,
                               double lon,
                               boolean isRadians)

Set the latitude, longitude for this point, with the option of noting whether the values are in degrees or radians.

Parameters:

lat - latitude

lon - longitude.

isRadians - true of values are radians.

getLongitude

public abstract float getLongitude()

Returns:

decimal degree longitude as a float.

getLatitude

public abstract float getLatitude()

Returns:

decimal degree latitude as a float.

getRadLon

public abstract double getRadLon()

Returns:

radian longitude value.

getRadLat

public abstract double getRadLat()

Returns:

radian latitude value.

setLatitude

public abstract void setLatitude(double lat)

Set decimal degree latitude.

setLongitude

public abstract void setLongitude(double lon)

Set decimal degree longitude.

setLatLon

public void setLatLon(LatLonPoint llp)

Set location values from another lat/lon point.

Parameters:

llp -

normalizeLatitude

public static final float normalizeLatitude(float lat)

Ensure latitude is between the poles.

Parameters:

lat -

Returns:

latitude greater than or equal to -90 and less than or equal to 90.

normalizeLatitude

public static final double normalizeLatitude(double lat)

Sets latitude to something sane.

Parameters:

lat - latitude in decimal degrees

Returns:

float normalized latitude in decimal degrees (−90° ≤ φ ≤ 90°)

wrapLongitude

public static final float wrapLongitude(float lon)

Ensure the longitude is between the date line.

Parameters:

lon -

Returns:

longitude that is smaller than or equal to 180 and greater than or equal to -180

wrapLongitude

public static final double wrapLongitude(double lon)

Sets longitude to something sane.

Parameters:

lon - longitude in decimal degrees

Returns:

float wrapped longitude in decimal degrees (−180° ≤ λ ≤ 180°)

isInvalidLatitude

public static boolean isInvalidLatitude(double lat)

Check if latitude is bogus. Latitude is invalid if lat > 90° or if lat < −90°.

Parameters:

lat - latitude in decimal degrees

Returns:

boolean true if latitude is invalid

isInvalidLongitude

public static boolean isInvalidLongitude(double lon)

Check if longitude is bogus. Longitude is invalid if lon > 180° or if lon < −180°.

Parameters:

lon - longitude in decimal degrees

Returns:

boolean true if longitude is invalid

equals

public boolean equals(java.lang.Object obj)

Determines whether two LatLonPoints are equal.

Overrides:

equals in class java.awt.geom.Point2D

Parameters:

obj - Object

Returns:

Whether the two points are equal up to a tolerance of 10 ^-5 degrees in latitude and longitude.

distance

public double distance(LatLonPoint toPoint)

Find the distance to another LatLonPoint, based on a earth spherical model.

Parameters:

toPoint - LatLonPoint

Returns:

distance, in radians. You can use an com.bbn.openmap.proj.Length to convert the radians to other units.

azimuth

public double azimuth(LatLonPoint toPoint)

Find the azimuth to another point, based on the spherical earth model.

Parameters:

toPoint - LatLonPoint

Returns:

the azimuth `Az' east of north from this point bearing toward the one provided as an argument.(-PI <= Az <= PI).

getPoint

public LatLonPoint getPoint(double distance,
                            double azimuth)

Get a new LatLonPoint a distance and azimuth from another point, based on the spherical earth model.

Parameters:

distance - radians

azimuth - radians

Returns:

LatLonPoint that is distance and azimuth away from this one.