ucar.unidata.geoloc.projection

Class Mercator

java.lang.Object

ucar.unidata.geoloc.ProjectionImpl

ucar.unidata.geoloc.projection.Mercator

All Implemented Interfaces:

Serializable, Projection

public class Mercator
extends ProjectionImpl

Mercator projection, spherical earth. Projection plane is a cylinder tangent to the earth at tangentLon. See John Snyder, Map Projections used by the USGS, Bulletin 1532, 2nd edition (1983), p 43-47

Author:

John Caron

See Also:

Projection, ProjectionImpl, Serialized Form

Field Summary

Fields inherited from class ucar.unidata.geoloc.ProjectionImpl

atts, defaultMapArea, 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
Mercator() Constructor with default parameters
Mercator(double lon0, double par) Construct a Mercator Projection.
Mercator(double lon0, double par, double false_easting, double false_northing)
Mercator(double lon0, double par, double false_easting, double false_northing, double radius) Construct a Mercator Projection.

Method Summary

Methods

Modifier and Type	Method and Description
ProjectionImpl	constructCopy() copy constructor - avoid clone !!
static double	convertScaleToStandardParallel(double scale) Convert "scale at standard parellel" to "standard parellel"
boolean	crossSeam(ProjectionPoint pt1, ProjectionPoint pt2) Does the line between these two points cross the projection "seam".
boolean	equals(Object o) Returns true if this represents the same Projection as proj.
double	getEarthRadius()
double	getFalseEasting() Get the false easting, in km.
double	getFalseNorthing() Get the false northing, in km.
double	getOriginLon() Get the origin longitude.
double	getParallel() Get the first standard parallel
int	hashCode()
ProjectionPoint	latLonToProj(LatLonPoint latLon, ProjectionPointImpl result) Convert a LatLonPoint to projection coordinates
String	paramsToString() Get the parameters as a String
LatLonPoint	projToLatLon(ProjectionPoint world, LatLonPointImpl result) Convert projection coordinates to a LatLonPoint Note: a new object is not created on each call for the return value.
void	setFalseEasting(double falseEasting) Set the false_easting, in km.
void	setFalseNorthing(double falseNorthing) Set the false northing, in km.
void	setOriginLon(double lon) Set the origin longitude.
void	setParallel(double par) Set the first standard parallel
String	toString() Get a String representation of this projection.

Methods inherited from class ucar.unidata.geoloc.ProjectionImpl

addParameter, addParameter, addParameter, findProjectionParameter, getClassName, getDefaultMapArea, getDefaultMapAreaLL, getHeader, getLatLonBoundingBox, getName, getProjectionParameters, getProjectionTypeLabel, isLatLon, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProjBB, projToLatLon, projToLatLon, projToLatLon, projToLatLon, projToLatLon, projToLatLon, projToLatLonBB, setDefaultMapArea, setName

Methods inherited from class java.lang.Object

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

Constructor Detail

Mercator

public Mercator()

Constructor with default parameters

Mercator

public Mercator(double lon0,
        double par)

Construct a Mercator Projection.

Parameters:

lon0 - longitude of origin (degrees)

par - standard parallel (degrees). cylinder cuts earth at this latitude.

Mercator

public Mercator(double lon0,
        double par,
        double false_easting,
        double false_northing)

Mercator

public Mercator(double lon0,
        double par,
        double false_easting,
        double false_northing,
        double radius)

Construct a Mercator Projection.

Parameters:

lon0 - longitude of origin (degrees)

par - standard parallel (degrees). cylinder cuts earth at this latitude.

false_easting - false_easting in km

false_northing - false_northing in km

radius - earth radius in km

Method Detail

convertScaleToStandardParallel

public static double convertScaleToStandardParallel(double scale)

Convert "scale at standard parellel" to "standard parellel"

Parameters:

scale - scale at standard parallel

Returns:

standard parallel in degrees

constructCopy

public ProjectionImpl constructCopy()

Description copied from class: ProjectionImpl

copy constructor - avoid clone !!

Specified by:

constructCopy in class ProjectionImpl

Returns:

a copy of this Projection

getParallel

public double getParallel()

Get the first standard parallel

Returns:

the first standard parallel

getOriginLon

public double getOriginLon()

Get the origin longitude.

Returns:

the origin longitude.

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()

setParallel

public void setParallel(double par)

Set the first standard parallel

Parameters:

par - the first standard parallel

setOriginLon

public void setOriginLon(double lon)

Set the origin longitude.

Parameters:

lon - the origin longitude.

setFalseEasting

public void setFalseEasting(double falseEasting)

Set the false_easting, in km. natural_x_coordinate + false_easting = x coordinate

Parameters:

falseEasting - x offset

setFalseNorthing

public void setFalseNorthing(double falseNorthing)

Set the false northing, in km. natural_y_coordinate + false_northing = y coordinate

Parameters:

falseNorthing - y offset

paramsToString

public String paramsToString()

Get the parameters as a String

Specified by:

paramsToString in interface Projection

Specified by:

paramsToString in class ProjectionImpl

Returns:

the parameters as a String

toString

public String toString()

Description copied from class: ProjectionImpl

Get a String representation of this projection.

Overrides:

toString in class ProjectionImpl

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)

crossSeam

public boolean crossSeam(ProjectionPoint pt1,
                ProjectionPoint pt2)

Does the line between these two points cross the projection "seam".

Specified by:

crossSeam in interface Projection

Specified by:

crossSeam in class ProjectionImpl

Parameters:

pt1 - the line goes between these two points

pt2 - the line goes between these two points

Returns:

false if there is no seam

equals

public boolean equals(Object o)

Description copied from class: ProjectionImpl

Returns true if this represents the same Projection as proj.

Specified by:

equals in interface Projection

Specified by:

equals in class ProjectionImpl

Parameters:

o - projection in question

Returns:

true if this represents the same Projection as proj.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

latLonToProj

public ProjectionPoint latLonToProj(LatLonPoint latLon,
                           ProjectionPointImpl result)

Convert a LatLonPoint to projection coordinates

Specified by:

latLonToProj in interface Projection

Specified by:

latLonToProj in class ProjectionImpl

Parameters:

latLon - convert from these lat, lon coordinates

result - the object to write to

Returns:

the given result

projToLatLon

public LatLonPoint projToLatLon(ProjectionPoint world,
                       LatLonPointImpl result)

Convert projection coordinates to a LatLonPoint Note: a new object is not created on each call for the return value.

Specified by:

projToLatLon in interface Projection

Specified by:

projToLatLon in class ProjectionImpl

Parameters:

world - convert from these projection coordinates

result - the object to write to

Returns:

LatLonPoint convert to these lat/lon coordinates