Package org.apache.sis.referencing.operation.projection

Class PolarStereographic

Object

FormattableObject

AbstractMathTransform

AbstractMathTransform2D

NormalizedProjection

PolarStereographic

All Implemented Interfaces:

Serializable, Parameterized, Lenient­Comparable, Math­Transform, Math­Transform2D

public class PolarStereographic
extends NormalizedProjection

Polar Stereographic projection (EPSG codes 9810, 9829, 9830). This is a special case of Oblique­Stereographic when the projection origin is at a pole.

EPSG defines three variants for this projection, A, B and C, which differ by the way the parameters are specified. The "Polar Stereographic (variant B)" projection includes a "Latitude of standard parallel" parameter where is effective the scale factor (normally 1). The "Polar Stereographic (variant A)" forces its "Latitude of natural origin" parameter to ±90°, depending on the hemisphere.

Since:

0.6

See Also:

Oblique­Stereographic, Serialized Form

Defined in the sis-referencing module

Nested Class Summary

Nested classes/interfaces inherited from class NormalizedProjection

Normalized­Projection.Parameter­Role

Field Summary

Fields inherited from class NormalizedProjection

eccentricity, eccentricity­Squared

Constructor Summary

Constructors

Constructor	Description
PolarStereographic(OperationMethod method, Parameters parameters)	Creates a Polar Stereographic projection from the given parameters.

Method Summary

Modifier and Type	Method	Description
MathTransform	createMapProjection(MathTransformFactory factory)	Returns the sequence of normalization → this → denormalization transforms as a whole.
protected void	inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff)	Converts the specified (x,y) coordinates and stores the result in dst­Pts (angles in radians).
Matrix	transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate)	Converts the specified (θ,φ) coordinate (units in radians) and stores the result in dst­Pts.

Methods inherited from class NormalizedProjection

compute­Hash­Code, equals, get­Contextual­Parameters, get­Parameter­Descriptors, get­Parameter­Values, inverse, try­Concatenate

Methods inherited from class AbstractMathTransform2D

create­Transformed­Shape, derivative, get­Source­Dimensions, get­Target­Dimensions, transform

Methods inherited from class AbstractMathTransform

derivative, equals, format­To, hash­Code, is­Identity, transform, transform, transform, transform, transform

Methods inherited from class FormattableObject

print, to­String, to­String, 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, transform, transform

Constructor Detail

PolarStereographic

public PolarStereographic(OperationMethod method,
                          Parameters parameters)

Creates a Polar Stereographic projection from the given parameters. The method argument can be the description of one of the following:

• "Polar Stereographic (Variant A)".
• "Polar Stereographic (Variant B)".
• "Polar Stereographic (Variant C)".

Parameters:

method - description of the projection parameters.

parameters - the parameter values of the projection to create.

Method Detail

createMapProjection

public MathTransform createMapProjection(MathTransformFactory factory)
                                  throws FactoryException

Returns the sequence of normalization → this → denormalization transforms as a whole. The transform returned by this method expects (longitude, latitude) coordinates in degrees and returns (x,y) coordinates in metres.

The non-linear part of the returned transform will be this transform, except if the ellipsoid is spherical. In the later case, this transform will be replaced by a simplified implementation.

Overrides:

create­Map­Projection in class Normalized­Projection

Parameters:

factory - the factory to use for creating the transform.

Returns:

the map projection from (λ,φ) to (x,y) coordinates.

Throws:

Factory­Exception - if an error occurred while creating a transform.

See Also:

Contextual­Parameters.complete­Transform(Math­Transform­Factory, Math­Transform)

transform

public Matrix transform(double[] srcPts,
                        int srcOff,
                        double[] dstPts,
                        int dstOff,
                        boolean derivate)
                 throws ProjectionException

Converts the specified (θ,φ) coordinate (units in radians) and stores the result in dst­Pts. In addition, opportunistically computes the projection derivative if derivate is true.

Specified by:

transform in class Normalized­Projection

Parameters:

src­Pts - the array containing the source point coordinate, as (longitude, latitude) angles in radians.

src­Off - the offset of the single coordinate to be converted in the source array.

dst­Pts - the array into which the converted coordinate is returned (may be the same than src­Pts). Coordinates will be expressed in a dimensionless unit, as a linear distance on a unit sphere or ellipse.

dst­Off - the offset of the location of the converted coordinate that is stored in the destination array.

derivate - true for computing the derivative, or false if not needed.

Returns:

the matrix of the projection derivative at the given source position, or null if the derivate argument is false.

Throws:

Projection­Exception - if the coordinate can not be converted.

See Also:

Abstract­Math­Transform.derivative(Direct­Position), Abstract­Math­Transform.transform(Direct­Position, Direct­Position), Math­Transforms.derivative­And­Transform(Math­Transform, double[], int, double[], int)

inverseTransform

protected void inverseTransform(double[] srcPts,
                                int srcOff,
                                double[] dstPts,
                                int dstOff)
                         throws ProjectionException

Converts the specified (x,y) coordinates and stores the result in dst­Pts (angles in radians).

Specified by:

inverse­Transform in class Normalized­Projection

Parameters:

src­Pts - the array containing the source point coordinate, as linear distance on a unit sphere or ellipse.

src­Off - the offset of the point to be converted in the source array.

dst­Pts - the array into which the converted point coordinate is returned (may be the same than src­Pts). Coordinates will be (longitude, latitude) angles in radians.

dst­Off - the offset of the location of the converted point that is stored in the destination array.

Throws:

Projection­Exception - if the point can not be converted.