ucar.unidata.geoloc.projection
Class AlbersEqualArea

java.lang.Object
  extended by ucar.unidata.geoloc.ProjectionImpl
      extended by ucar.unidata.geoloc.projection.AlbersEqualArea
All Implemented Interfaces:
Serializable, Cloneable, Projection

public class AlbersEqualArea
extends ProjectionImpl

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

Author:
Unidata Development Team
See Also:
Projection, 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
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
 Object clone()
          Clone this projection.
 ProjectionImpl 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 proj)
          Check for equality with the Object in question
 double getEarthRadius()
           
 double getFalseEasting()
          Get the false easting, in km.
 double getFalseNorthing()
          Get the false northing, in km.
 double getOriginLat()
          Get the origin latitude.
 double getOriginLon()
          Get the origin longitude.
 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 for the lat.
 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
static void main(String[] args)
          Test
 String paramsToString()
          Create a String of the parameters.
 double[][] projToLatLon(double[][] from, double[][] to)
          Convert lat/lon coordinates to projection coordinates.
 float[][] projToLatLon(float[][] from, float[][] to)
          Convert lat/lon coordinates to projection coordinates.
 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 setOriginLat(double lat)
          Set the origin latitude.
 void setOriginLon(double lon)
          Set the origin longitude.
 void setParallelOne(double par)
          Set the first standard parallel
 void setParallelTwo(double par)
          Set the second standard parallel
 
Methods inherited from class ucar.unidata.geoloc.ProjectionImpl
addParameter, addParameter, addParameter, getClassName, getDefaultMapArea, getDefaultMapAreaLL, getHeader, getLatLonBoundingBox, getName, getProjectionParameters, isLatLon, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProj, latLonToProjBB, projToLatLon, projToLatLon, projToLatLon, projToLatLon, projToLatLonBB, setDefaultMapArea, setName, toString
 
Methods inherited from class java.lang.Object
finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

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 ProjectionImpl constructCopy()
copy constructor - avoid clone !!

Specified by:
constructCopy in class ProjectionImpl
Returns:
a copy of this Projection

clone

public Object clone()
Clone this projection.

Overrides:
clone in class ProjectionImpl
Returns:
Clone of this

equals

public boolean equals(Object proj)
Check for equality with the Object in question

Specified by:
equals in interface Projection
Specified by:
equals in class ProjectionImpl
Parameters:
proj - object to check
Returns:
true if they are equal

getParallelTwo

public double getParallelTwo()
Get the second standard parallel

Returns:
the second standard parallel

setParallelTwo

public void setParallelTwo(double par)
Set the second standard parallel

Parameters:
par - the second standard parallel

getParallelOne

public double getParallelOne()
Get the first standard parallel

Returns:
the first standard parallel

setParallelOne

public void setParallelOne(double par)
Set the first standard parallel

Parameters:
par - the first standard parallel

getOriginLon

public double getOriginLon()
Get the origin longitude.

Returns:
the origin longitude.

setOriginLon

public void setOriginLon(double lon)
Set the origin longitude.

Parameters:
lon - the origin longitude.

getOriginLat

public double getOriginLat()
Get the origin latitude.

Returns:
the origin latitude.

setOriginLat

public void setOriginLat(double lat)
Set the origin latitude.

Parameters:
lat - the origin latitude.

getFalseEasting

public double getFalseEasting()
Get the false easting, in km.

Returns:
the false easting.

setFalseEasting

public void setFalseEasting(double falseEasting)
Set the false_easting, in km. natural_x_coordinate + false_easting = x coordinate

Parameters:
falseEasting - x offset

getFalseNorthing

public double getFalseNorthing()
Get the false northing, in km.

Returns:
the false northing.

setFalseNorthing

public void setFalseNorthing(double falseNorthing)
Set the false northing, in km. natural_y_coordinate + false_northing = y coordinate

Parameters:
falseNorthing - y offset

getEarthRadius

public double getEarthRadius()

getProjectionTypeLabel

public 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 String paramsToString()
Create a String of the parameters.

Specified by:
paramsToString in interface Projection
Specified by:
paramsToString in class ProjectionImpl
Returns:
a String of the parameters

getScale

public double getScale(double lat)
Get the scale for the lat.

Parameters:
lat - lat to use
Returns:
scale

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.

Specified by:
crossSeam in interface Projection
Specified by:
crossSeam in class ProjectionImpl
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,
                                    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

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[0][i], from[1][i] is the (lat,lon) coordinate of the ith point
to - resulting array of projection coordinates, where to[0][i], to[1][i] is the (x,y) coordinate of the ith point
latIndex - index of latitude in "from"
lonIndex - index of longitude in "from"
Returns:
the "to" array.

projToLatLon

public float[][] projToLatLon(float[][] from,
                              float[][] to)
Convert lat/lon coordinates to projection coordinates.

Overrides:
projToLatLon in class ProjectionImpl
Parameters:
from - array of lat/lon coordinates: from[2][n], where (from[0][i], from[1][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
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[0][i], from[1][i] is the (lat,lon) coordinate of the ith point
to - resulting array of projection coordinates, where to[0][i], to[1][i] is the (x,y) coordinate of the ith point
latIndex - index of latitude in "from"
lonIndex - index of longitude in "from"
Returns:
the "to" array.

projToLatLon

public double[][] projToLatLon(double[][] from,
                               double[][] to)
Convert lat/lon coordinates to projection coordinates.

Overrides:
projToLatLon in class ProjectionImpl
Parameters:
from - array of lat/lon coordinates: from[2][n], where (from[0][i], from[1][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
Returns:
the "to" array

main

public static void main(String[] args)
Test

Parameters:
args - not used


Copyright © 1999-2011 UCAR/Unidata. All Rights Reserved.