Package org.geotools.referencing.operation.projection

Class Polyconic.Spherical

Object

Formattable

AbstractMathTransform

MapProjection

Polyconic.Abstract

Spherical

All Implemented Interfaces:

Serializable, MathTransform, MathTransform2D

Enclosing class:

Polyconic

public static class Polyconic.Spherical
extends Polyconic.Abstract

Ellipsoidal Polyconic projection.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class MapProjection

MapProjection.AbstractProvider

Field Summary

Fields inherited from class Polyconic.Abstract

ml0

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	Spherical(ParameterValueGroup parameters)	Constructs a new map projection from the supplied parameters.

Method Summary

Modifier and Type	Method	Description
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 coordinate and stores the result in ptDst.

Methods inherited from class Polyconic.Abstract

equals, getParameterDescriptors, getToleranceForAssertions, hashCode

Methods inherited from class MapProjection

checkReciprocal, getParameterValues, getSourceDimensions, getTargetDimensions, 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

Spherical

protected Spherical(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

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.

transformNormalized

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

Description copied from class: MapProjection

Transforms the specified coordinate and stores the result in ptDst. This method is usually (but not guaranteed) to be invoked with values of x in the range [-PI..PI] and values of y in the range [-PI/2..PI/2]. Values outside those ranges are accepted (sometime with a warning logged) on the assumption that most implementations use those values only in trigonometric functions like sin and cos.

Coordinates have the MapProjection.centralMeridian removed from lambda before this method is invoked. After this method is invoked, the results in ptDst are multiplied by MapProjection.globalScale, and the MapProjection.falseEasting and MapProjection.falseNorthing are added. 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_fwd.c. Therefore when porting projections from PROJ.4, the forward 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 remove the MapProjection.centralMeridian from lambda or apply the MapProjection.semiMajor (a or R).

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.