ucar.unidata.geoloc.projection
Class LatLonProjection

java.lang.Object
  ucar.unidata.geoloc.ProjectionImpl
      ucar.unidata.geoloc.projection.LatLonProjection

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Projection

public class LatLonProjection
extends ProjectionImpl

This is the "fake" identity projection where world coord = latlon coord. Topologically its the same as a cylinder tangent to the earth at the equator. The cylinder is cut at the "seam" = centerLon +- 180. Longitude values are always kept in the range [centerLon +-180]

Author:

John Caron

See Also:

ProjectionImpl, Serialized Form

Field Summary

Fields inherited from class ucar.unidata.geoloc.ProjectionImpl

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

Constructor Summary

LatLonProjection()
Default constructor

LatLonProjection(java.lang.String name)
Create a new LatLonProjection

LatLonProjection(java.lang.String name, ProjectionRect defaultMapArea)
Create a new LatLonProjection

Method Summary

java.lang.Object	clone() Clone this projection
ProjectionImpl	constructCopy() copy constructor - avoid clone !!
boolean	crossSeam(ProjectionPoint pt1, ProjectionPoint pt2) Does the line between these two points cross the projection "seam".
boolean	equals(java.lang.Object p) See if this projection equals the object in question
double	getCenterLon() Get the center of the Longitude range.
java.lang.String	getClassName() Get the class name
java.lang.String	getProjectionTypeLabel() Get the label to be used in the gui for this type of projection
double[][]	latLonToProj(double[][] from, double[][] to, int latIndex, int lonIndex) Convert lat/lon coordinates to projection coordinates.
float[][]	latLonToProj(float[][] from, float[][] to, int latIndex, int lonIndex) Convert lat/lon coordinates to projection coordinates.
ProjectionPoint	latLonToProj(LatLonPoint latlon, ProjectionPointImpl result) Convert a LatLonPoint to projection coordinates
ProjectionRect[]	latLonToProjRect(double lat0, double lon0, double lat1, double lon1) Create a latlon rectangle and split it into the equivalent ProjectionRect using this LatLonProjection.
ProjectionRect[]	latLonToProjRect(LatLonRect latlonR) Split a latlon rectangle to the equivalent ProjectionRect using this LatLonProjection to split it at the seam if needed.
java.lang.String	paramsToString() Get a String of the parameters
double[][]	projToLatLon(double[][] from, double[][] to) Convert projection coordinates to lat/lon coordinate.
float[][]	projToLatLon(float[][] from, float[][] to) Convert projection coordinates to lat/lon coordinate.
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.
LatLonRect	projToLatLonBB(ProjectionRect world) Convert a world coordinate bounding box to a lat/lon bounding box, by finding the minimum enclosing box.
double	setCenterLon(double centerLon) Set the center of the Longitude range.
void	setDefaultMapArea(ProjectionRect bb) Set a reasonable bounding box for this projection.

Methods inherited from class ucar.unidata.geoloc.ProjectionImpl

addParameter, addParameter, addParameter, getDefaultMapArea, getDefaultMapAreaLL, getHeader, getLatLonBoundingBox, getName, getProjectionParameters, isLatLon, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProjBB, projToLatLon, projToLatLon, projToLatLon, projToLatLon, setName, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

LatLonProjection

public LatLonProjection()

Default constructor

LatLonProjection

public LatLonProjection(java.lang.String name)

Create a new LatLonProjection

Parameters:

name - name of projection

LatLonProjection

public LatLonProjection(java.lang.String name,
                        ProjectionRect defaultMapArea)

Create a new LatLonProjection

Parameters:

name - name of projection

defaultMapArea - bounding box

Method Detail

constructCopy

public ProjectionImpl constructCopy()

copy constructor - avoid clone !!

Specified by:

constructCopy in class ProjectionImpl

Returns:

a copy of this Projection

getClassName

public java.lang.String getClassName()

Get the class name

Specified by:

getClassName in interface Projection

Overrides:

getClassName in class ProjectionImpl

Returns:

class name

getProjectionTypeLabel

public java.lang.String getProjectionTypeLabel()

Get the label to be used in the gui for this type of projection

Overrides:

getProjectionTypeLabel in class ProjectionImpl

Returns:

Type label

paramsToString

public java.lang.String paramsToString()

Get a String of the parameters

Specified by:

paramsToString in interface Projection

Specified by:

paramsToString in class ProjectionImpl

Returns:

a String of the parameters

equals

public boolean equals(java.lang.Object p)

See if this projection equals the object in question

Specified by:

equals in interface Projection

Specified by:

equals in class ProjectionImpl

Parameters:

p - object in question

Returns:

true if it is a LatLonProjection and covers the same area

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

projToLatLon

public float[][] projToLatLon(float[][] from,
                              float[][] to)

Convert projection coordinates to lat/lon coordinate.

Overrides:

projToLatLon in class ProjectionImpl

Parameters:

from - array of projection coordinates: from[2][n], where (from[0][i], from[1][i]) is the (x, y) coordinate of the ith point

to - resulting array of lat/lon coordinates: to[2][n] where (to[0][i], to[1][i]) is the (lat, lon) coordinate of the ith point

Returns:

the "to" array

latLonToProj

public float[][] latLonToProj(float[][] from,
                              float[][] to,
                              int latIndex,
                              int lonIndex)

Convert lat/lon coordinates to projection coordinates.

Overrides:

latLonToProj in class ProjectionImpl

Parameters:

from - array of lat/lon coordinates: from[2][n], where (from[latIndex][i], from[lonIndex][i]) is the (lat,lon) coordinate of the ith point

to - resulting array of projection coordinates: to[2][n] where (to[0][i], to[1][i]) is the (x,y) coordinate of the ith point

latIndex - index of lat coordinate; must be 0 or 1

lonIndex - index of lon coordinate; must be 0 or 1

Returns:

the "to" array

projToLatLon

public double[][] projToLatLon(double[][] from,
                               double[][] to)

Convert projection coordinates to lat/lon coordinate.

Overrides:

projToLatLon in class ProjectionImpl

Parameters:

from - array of projection coordinates: from[2][n], where (from[0][i], from[1][i]) is the (x, y) coordinate of the ith point

to - resulting array of lat/lon coordinates: to[2][n] where (to[0][i], to[1][i]) is the (lat, lon) coordinate of the ith point

Returns:

the "to" array

latLonToProj

public double[][] latLonToProj(double[][] from,
                               double[][] to,
                               int latIndex,
                               int lonIndex)

Convert lat/lon coordinates to projection coordinates.

Overrides:

latLonToProj in class ProjectionImpl

Parameters:

from - array of lat/lon coordinates: from[2][n], where (from[latIndex][i], from[lonIndex][i]) is the (lat,lon) coordinate of the ith point

to - resulting array of projection coordinates: to[2][n] where (to[0][i], to[1][i]) is the (x,y) coordinate of the ith point

latIndex - index of lat coordinate; must be 0 or 1

lonIndex - index of lon coordinate; must be 0 or 1

Returns:

the "to" array

clone

public java.lang.Object clone()

Clone this projection

Overrides:

clone in class ProjectionImpl

Returns:

a clone of this projection

setCenterLon

public double setCenterLon(double centerLon)

Set the center of the Longitude range. It is normalized to +/- 180. The cylinder is cut at the "seam" = centerLon +- 180. Use this to keep the Longitude values kept in the range [centerLon +-180], which makes seam handling easier.

Parameters:

centerLon - the center of the Longitude range.

Returns:

centerLon normalized to +/- 180.

getCenterLon

public double getCenterLon()

Get the center of the Longitude range. It is normalized to +/- 180.

Returns:

the center longitude

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

setDefaultMapArea

public void setDefaultMapArea(ProjectionRect bb)

Set a reasonable bounding box for this projection.

Overrides:

setDefaultMapArea in class ProjectionImpl

Parameters:

bb - a reasonable bounding box

latLonToProjRect

public ProjectionRect[] latLonToProjRect(LatLonRect latlonR)

Split a latlon rectangle to the equivalent ProjectionRect using this LatLonProjection to split it at the seam if needed.

Parameters:

latlonR - the latlon rectangle to transform

Returns:

1 or 2 ProjectionRect. If it doesnt cross the seam, the second rectangle is null.

projToLatLonBB

public LatLonRect projToLatLonBB(ProjectionRect world)

Description copied from class: ProjectionImpl

Convert a world coordinate bounding box to a lat/lon bounding box, by finding the minimum enclosing box.

Overrides:

projToLatLonBB in class ProjectionImpl

Parameters:

world - input world coordinate bounding box

Returns:

minimum enclosing box in lat,lon coordinates.

latLonToProjRect

public ProjectionRect[] latLonToProjRect(double lat0,
                                         double lon0,
                                         double lat1,
                                         double lon1)

Create a latlon rectangle and split it into the equivalent ProjectionRect using this LatLonProjection. The latlon rect is constructed from 2 lat/lon points. The lon values are considered coords in the latlonProjection, and so do not have to be +/- 180.

Parameters:

lat0 - lat of point 1

lon0 - lon of point 1

lat1 - lat of point 1

lon1 - lon of point 1

Returns:

1 or 2 ProjectionRect. If it doesnt cross the seam, the second rectangle is null.