Package org.geotools.referencing.operation.projection

Class WinkelTripel

Object

Formattable

AbstractMathTransform

MapProjection

WinkelTripel

All Implemented Interfaces:

Serializable, MathTransform, MathTransform2D

public class WinkelTripel
extends MapProjection

Winkel Tripel and Hammer Aitoff projection

References:

• http://en.wikipedia.org/wiki/Winkel_tripel_projection
• http://en.wikipedia.org/wiki/Hammer_projection

Since:

2.6.3

Author:

Andrea Aime

See Also:

Polyconic projection on MathWorld, "Polyconic" on RemoteSensing.org, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	WinkelTripel.AitoffProvider	The math transform provider for the Aitoff projection (not part of the EPSG database).
static class	WinkelTripel.WinkelProvider	The math transform provider for the Winkle Tripel projection projection (not part of the EPSG database).

Nested classes/interfaces inherited from class MapProjection

MapProjection.AbstractProvider

Field Summary

Fields inherited from class MapProjection

centralMeridian, en0, en1, en2, en3, en4, excentricity, excentricitySquared, falseEasting, falseNorthing, globalScale, invertible, isSpherical, latitudeOfOrigin, LOGGER, scaleFactor, semiMajor, semiMinor, SKIP_SANITY_CHECKS

Fields inherited from class Formattable

SINGLE_LINE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	WinkelTripel(WinkelTripel.ProjectionMode mode, ParameterDescriptorGroup descriptors, ParameterValueGroup parameters)	Constructs a new map projection from the supplied parameters.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object object)	Compares the specified object with this map projection for equality.
ParameterDescriptorGroup	getParameterDescriptors()	Returns the parameter descriptors for this map projection.
int	hashCode()	Returns a hash value for this projection.
protected Point2D	inverseTransformNormalized(double x, double y, Point2D ptDst)	Transforms the specified coordinate and stores the result in ptDst.
protected Point2D	transformNormalized(double lam, double phi, Point2D ptDst)	Transforms the specified (λ,φ) coordinates (units in radians) and stores the result in ptDst (linear distance on a unit sphere).

Methods inherited from class MapProjection

checkReciprocal, getParameterValues, getSourceDimensions, getTargetDimensions, getToleranceForAssertions, inv_mlfn, inverse, mlfn, orthodromicDistance, resetWarnings, transform, transform, transform

Methods inherited from class AbstractMathTransform

createTransformedShape, derivative, derivative, ensureNonNull, formatWKT, getName, isIdentity, needCopy, normalizeAngle, rollLongitude, transform, transform, transform

Methods inherited from class Formattable

cleanupThreadLocals, toString, toWKT, toWKT, toWKT, toWKT

Methods inherited from class Object

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

Methods inherited from interface MathTransform

derivative, isIdentity, toWKT, transform, transform, transform

Methods inherited from interface MathTransform2D

createTransformedShape, derivative

Constructor Detail

WinkelTripel

protected WinkelTripel(WinkelTripel.ProjectionMode mode,
                       ParameterDescriptorGroup descriptors,
                       ParameterValueGroup parameters)
                throws ParameterNotFoundException

Constructs a new map projection from the supplied parameters.

Parameters:

parameters - The parameter values in standard units.

Throws:

ParameterNotFoundException - if a mandatory parameter is missing.

Method Detail

getParameterDescriptors

public ParameterDescriptorGroup getParameterDescriptors()

Returns the parameter descriptors for this map projection. This is used for a providing a default implementation of MapProjection.getParameterValues(), as well as arguments checking.

Specified by:

getParameterDescriptors in class MapProjection

Returns:

The parameter descriptors for this math transform, or null.

See Also:

OperationMethod.getParameters()

transformNormalized

protected Point2D transformNormalized(double lam,
                                      double phi,
                                      Point2D ptDst)
                               throws ProjectionException

Transforms the specified (λ,φ) coordinates (units in radians) and stores the result in ptDst (linear distance on a unit sphere).

Specified by:

transformNormalized in class MapProjection

Parameters:

lam - The longitude of the coordinate, in radians.

phi - The latitude of the coordinate, in radians.

ptDst - the specified coordinate point that stores the result of transforming ptSrc, or null. Ordinates will be in a dimensionless unit, as a linear distance on a unit sphere or ellipse.

Returns:

the coordinate point after transforming (lambda, phi) and storing the result in ptDst.

Throws:

ProjectionException - if the point can't be transformed.

inverseTransformNormalized

protected Point2D inverseTransformNormalized(double x,
                                             double y,
                                             Point2D ptDst)
                                      throws ProjectionException

Description copied from class: MapProjection

Transforms the specified coordinate and stores the result in ptDst. This method returns longitude as x values in the range [-PI..PI] and latitude as y values in the range [-PI/2..PI/2]. It will be checked by the caller, so this method doesn't need to performs this check.

Input coordinates have the MapProjection.falseEasting and MapProjection.falseNorthing removed and are divided by MapProjection.globalScale before this method is invoked. After this method is invoked, the MapProjection.centralMeridian is added to the x results in ptDst. This means that projections that implement this method are performed on an ellipse (or sphere) with a semi-major axis of 1.

In PROJ.4, the same standardization, described above, is handled by pj_inv.c. Therefore when porting projections from PROJ.4, the inverse transform equations can be used directly here with minimal change. In the equations of Snyder, MapProjection.falseEasting, MapProjection.falseNorthing and MapProjection.scaleFactor are usually not given. When implementing these equations here, you will not need to add the MapProjection.centralMeridian to the output longitude or remove the MapProjection.semiMajor (a or R).

Specified by:

inverseTransformNormalized in class MapProjection

Parameters:

x - The easting of the coordinate, linear distance on a unit sphere or ellipse.

y - The northing of the coordinate, linear distance on a unit sphere or ellipse.

ptDst - the specified coordinate point that stores the result of transforming ptSrc, or null. Ordinates will be in radians.

Returns:

the coordinate point after transforming x, y and storing the result in ptDst.

Throws:

ProjectionException - if the point can't be transformed.

hashCode

public int hashCode()

Returns a hash value for this projection.

Overrides:

hashCode in class MapProjection

equals

public boolean equals(Object object)

Compares the specified object with this map projection for equality.

Overrides:

equals in class MapProjection

Parameters:

object - The object to compare with this transform.

Returns:

true if the given object is a transform of the same class and if, given identical source position, the transformed position would be the equals.