ucar.unidata.geoloc.projection

Class AlbersEqualArea

java.lang.Object

ucar.unidata.geoloc.projection.AbstractProjection

ucar.unidata.geoloc.projection.AlbersEqualArea

All Implemented Interfaces:

Projection

@Immutable
public class AlbersEqualArea
extends AbstractProjection

Albers Equal Area Conic Projection, one or two standard parallels, spherical earth. See John Snyder, Map Projections used by the USGS, Bulletin 1532, 2nd edition (1983), p 98

Field Summary

Fields inherited from class ucar.unidata.geoloc.projection.AbstractProjection

atts, EARTH_RADIUS, INDEX_LAT, INDEX_LON, INDEX_X, INDEX_Y, isLatLon, name, PI, PI_OVER_2, PI_OVER_4, TOLERANCE

Constructor Summary

Constructors

Constructor and Description
AlbersEqualArea() Constructor with default parameters
AlbersEqualArea(double lat0, double lon0, double par1, double par2) Construct a AlbersEqualArea Projection, two standard parellels.
AlbersEqualArea(double lat0, double lon0, double par1, double par2, double falseEasting, double falseNorthing) Construct a AlbersEqualArea Projection, two standard parellels.
AlbersEqualArea(double lat0, double lon0, double par1, double par2, double falseEasting, double falseNorthing, double earth_radius) Construct a AlbersEqualArea Projection, two standard parellels.

Method Summary

Modifier and Type	Method and Description
Projection	constructCopy() copy constructor - avoid clone !!
boolean	crossSeam(ProjectionPoint pt1, ProjectionPoint pt2) This returns true when the line between pt1 and pt2 crosses the seam.
boolean	equals(Object o)
double	getEarthRadius() Earth radius in km
double	getFalseEasting() Get the false easting, in km.
double	getFalseNorthing() Get the false northing, in km.
double	getOriginLat() Get the origin latitude in degrees.
double	getOriginLon() Get the origin longitude in degrees.
double	getParallelOne() Get the first standard parallel
double	getParallelTwo() Get the second standard parallel
String	getProjectionTypeLabel() Get the label to be used in the gui for this type of projection.
double	getScale(double lat) Get the scale at the given lat.
int	hashCode()
ProjectionPoint	latLonToProj(LatLonPoint latLon) Convert a LatLonPoint to projection coordinates.
String	paramsToString() String representation of the projection parameters.
LatLonPoint	projToLatLon(ProjectionPoint world) Convert projection coordinates to a LatLonPoint.
String	toString() Get a String representation of this projection.

Methods inherited from class ucar.unidata.geoloc.projection.AbstractProjection

addParameter, addParameter, addParameter, addParameter, findProjectionParameter, getClassName, getHeader, getMinOrMaxLon, getName, getProjectionAttributes, getProjectionParameters, isLatLon, latLonToProjBB, projToLatLonBB

Methods inherited from class java.lang.Object

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

Methods inherited from interface ucar.unidata.geoloc.Projection

latLonToProj, projToLatLon

Constructor Detail

AlbersEqualArea

public AlbersEqualArea()

Constructor with default parameters

AlbersEqualArea

public AlbersEqualArea(double lat0,
                       double lon0,
                       double par1,
                       double par2)

Construct a AlbersEqualArea Projection, two standard parellels. For the one standard parellel case, set them both to the same value.

Parameters:

lat0 - lat origin of the coord. system on the projection plane

lon0 - lon origin of the coord. system on the projection plane

par1 - standard parallel 1

par2 - standard parallel 2

Throws:

IllegalArgumentException - if lat0, par1, par2 = +/-90 deg

AlbersEqualArea

public AlbersEqualArea(double lat0,
                       double lon0,
                       double par1,
                       double par2,
                       double falseEasting,
                       double falseNorthing)

Construct a AlbersEqualArea Projection, two standard parellels. For the one standard parellel case, set them both to the same value.

Parameters:

lat0 - lat origin of the coord. system on the projection plane

lon0 - lon origin of the coord. system on the projection plane

par1 - standard parallel 1

par2 - standard parallel 2

falseEasting - false easting in km

falseNorthing - false easting in km

Throws:

IllegalArgumentException - if lat0, par1, par2 = +/-90 deg

AlbersEqualArea

public AlbersEqualArea(double lat0,
                       double lon0,
                       double par1,
                       double par2,
                       double falseEasting,
                       double falseNorthing,
                       double earth_radius)

Construct a AlbersEqualArea Projection, two standard parellels. For the one standard parellel case, set them both to the same value.

Parameters:

lat0 - lat origin of the coord. system on the projection plane

lon0 - lon origin of the coord. system on the projection plane

par1 - standard parallel 1

par2 - standard parallel 2

falseEasting - false easting in km

falseNorthing - false easting in km

earth_radius - radius of the earth in km

Throws:

IllegalArgumentException - if lat0, par1, par2 = +/-90 deg

Method Detail

constructCopy

public Projection constructCopy()

copy constructor - avoid clone !!

Specified by:

constructCopy in class AbstractProjection

Returns:

a copy of this Projection.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

getParallelTwo

public double getParallelTwo()

Get the second standard parallel

Returns:

the second standard parallel

getParallelOne

public double getParallelOne()

Get the first standard parallel

Returns:

the first standard parallel

getOriginLon

public double getOriginLon()

Get the origin longitude in degrees.

Returns:

the origin longitude in degrees.

getOriginLat

public double getOriginLat()

Get the origin latitude in degrees.

Returns:

the origin latitude in degrees.

getFalseEasting

public double getFalseEasting()

Get the false easting, in km.

Returns:

the false easting.

getFalseNorthing

public double getFalseNorthing()

Get the false northing, in km.

Returns:

the false northing.

getEarthRadius

public double getEarthRadius()

Earth radius in km

Returns:

Earth radius in km

getProjectionTypeLabel

public String getProjectionTypeLabel()

Description copied from class: AbstractProjection

Get the label to be used in the gui for this type of projection. This defaults to call getClassName

Overrides:

getProjectionTypeLabel in class AbstractProjection

Returns:

Type label

paramsToString

public String paramsToString()

Description copied from interface: Projection

String representation of the projection parameters.

Specified by:

paramsToString in interface Projection

Specified by:

paramsToString in class AbstractProjection

toString

public String toString()

Description copied from class: AbstractProjection

Get a String representation of this projection.

Overrides:

toString in class AbstractProjection

Returns:

the name of the projection. This is what gets displayed when you add the projection object to a UI widget (e.g. label, combobox)

getScale

public double getScale(double lat)

Get the scale at the given lat.

Parameters:

lat - lat to use

Returns:

scale factor at that latitude

crossSeam

public boolean crossSeam(ProjectionPoint pt1,
                         ProjectionPoint pt2)

This returns true when the line between pt1 and pt2 crosses the seam. When the cone is flattened, the "seam" is lon0 +- 180.

Parameters:

pt1 - point 1

pt2 - point 2

Returns:

true when the line between pt1 and pt2 crosses the seam.

latLonToProj

public ProjectionPoint latLonToProj(LatLonPoint latLon)

Description copied from interface: Projection

Convert a LatLonPoint to projection coordinates.

projToLatLon

public LatLonPoint projToLatLon(ProjectionPoint world)

Description copied from interface: Projection

Convert projection coordinates to a LatLonPoint.