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

Class ObliqueMercator

Object

FormattableObject

AbstractMathTransform

AbstractMathTransform2D

NormalizedProjection

ObliqueMercator

All Implemented Interfaces:

Serializable, Parameterized, Lenient­Comparable, Math­Transform, Math­Transform2D

public class ObliqueMercator
extends NormalizedProjection

Oblique Mercator projection (EPSG codes 9812, 9815). The Oblique Mercator projection can be seen as a generalization of Mercator and Transverse­Mercator projections when the central line is not along the equator or a meridian, respectively. This class covers also the Rectified Skew Orthomorphic (RSO) case.

There is different ways to specify the projection parameters:

• Variant A (EPSG:9812) uses false easting/northing defined at the natural origin of the coordinate system.
• Variant B (EPSG:9815) uses false easting/northing defined at the projection center.
• ESRI "Two Points" variant defines the central line with two points instead of with an azimuth angle.

Azimuth values of 0 and ±90 degrees are allowed, but for such cases the Mercator and Transverse­Mercator projections should be preferred, both for performance and accuracy reasons.

Since:

1.0

See Also:

• Mercator
• Transverse­Mercator
• 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

Fields inherited from class AbstractMathTransform2D

DIMENSION

Constructor Summary

Constructors

Constructor	Description
Oblique­Mercator(Operation­Method method, Parameters parameters)	Creates an Oblique Mercator projection from the given parameters.

Method Summary

Modifier and Type	Method	Description
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 (λ,φ) coordinate (units in radians) and stores the result in dst­Pts.

Methods inherited from class NormalizedProjection

compute­Hash­Code, create­Map­Projection, 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 Details

ObliqueMercator

public ObliqueMercator(OperationMethod method,
 Parameters parameters)

Creates an Oblique Mercator projection from the given parameters. The method argument can be the description of one of the following:

• "Hotine Oblique Mercator (variant A)".
• "Hotine Oblique Mercator (variant B)".
• "Hotine Oblique Mercator two point center" (from ESRI).
• "Hotine Oblique Mercator two point natural origin" (from ESRI).
• "Rectified Skew Orthomorphic".

Parameters:

method - description of the projection parameters.

parameters - the parameter values of the projection to create.

Method Details

transform

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

Converts the specified (λ,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.