org.geotoolkit.referencing.operation.projection
Class Equirectangular

Object
  FormattableObject
      AbstractMathTransform
          AbstractMathTransform2D
              UnitaryProjection
                  Equirectangular

All Implemented Interfaces:

Serializable, Formattable, Parameterized, LenientComparable, MathTransform, MathTransform2D

@Immutable
public class Equirectangular
extends UnitaryProjection

Equidistant Cylindrical projection (EPSG codes 1028, 1029, 9842, 9823). See the Cylindrical Equidistant projection on MathWorld for an overview. See any of the following providers for a list of programmatic parameters:

• EquidistantCylindrical
• PlateCarree

Description
In the particular case where the latitude of natural origin is at the equator, this projection is also called Plate Carrée. This is used for example in WGS84 / Plate Carrée (EPSG:32662).

References

• John P. Snyder (Map Projections - A Working Manual,
  U.S. Geological Survey Professional Paper 1395, 1987)
• "Coordinate Conversions and Transformations including Formulas",
  EPSG Guidance Note Number 7 part 2, Version 24.

Since:

2.2

Version:

3.00

Author:

John Grange, Martin Desruisseaux (IRD, Geomatys)

See Also:

Serialized Form

Module:

referencing/geotk-referencing (download)

View source code for this class

Nested Class Summary

Nested classes/interfaces inherited from class UnitaryProjection

UnitaryProjection.Parameters

Field Summary

Fields inherited from class UnitaryProjection

excentricity, excentricitySquared

Fields inherited from class FormattableObject

EPSG, GEOTIFF, INTERNAL, OGC, SINGLE_LINE

Constructor Summary

protected

Equirectangular(UnitaryProjection.Parameters parameters) Constructs a new map projection from the supplied parameters.

Method Summary

static MathTransform2D	create(ParameterDescriptorGroup descriptor, ParameterValueGroup values) Creates an Equidistant Cylindrical projection from the given parameters.
ParameterDescriptorGroup	getParameterDescriptors() Returns the parameter descriptors for this unitary projection.
protected void	inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) Transforms the specified (x,y) coordinates and stores the result in dstPts (angles in radians).
boolean	isIdentity() Returns true if this unitary projection is the identity transform.
protected void	transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) Transforms the specified (λ,φ) coordinates (units in radians) and stores the result in dstPts (linear distance on a unit sphere).
void	transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts) Converts a list of coordinate point ordinal values.

Methods inherited from class UnitaryProjection

computeHashCode, equals, finish, getParameterValues, getUnmarshalledParameters, inverse, resetWarnings, rollLongitude, unrollLongitude

Methods inherited from class AbstractMathTransform2D

getSourceDimensions, getTargetDimensions, transform

Methods inherited from class AbstractMathTransform

createTransformedShape, derivative, derivative, ensureNonNull, equals, formatWKT, getName, hashCode, rollLongitude, transform, transform, transform, transform

Methods inherited from class FormattableObject

getDefaultIndentation, print, setDefaultIndentation, toString, toWKT, toWKT, toWKT

Methods inherited from class Object

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

Methods inherited from interface MathTransform2D

createTransformedShape, derivative

Methods inherited from interface MathTransform

derivative, toWKT, transform, transform, transform, transform

Constructor Detail

Equirectangular

protected Equirectangular(UnitaryProjection.Parameters parameters)

Constructs a new map projection from the supplied parameters.

Parameters:

parameters - The parameters of the projection to be created.

Method Detail

create

public static MathTransform2D create(ParameterDescriptorGroup descriptor,
                                     ParameterValueGroup values)

Creates an Equidistant Cylindrical projection from the given parameters. The descriptor argument is usually one of the PARAMETERS constants defined in the EquidistantCylindrical class or a subclass, but is not restricted to. If a different descriptor is supplied, it is user's responsibility to ensure that it is suitable to an Equidistant Cylindrical projection.

Parameters:

descriptor - Typically EquidistantCylindrical.PARAMETERS.

values - The parameter values of the projection to create.

Returns:

The map projection.

Since:

3.00

getParameterDescriptors

public ParameterDescriptorGroup getParameterDescriptors()

Returns the parameter descriptors for this unitary projection. Note that the returned descriptor is about the unitary projection, not the full one.

Specified by:

getParameterDescriptors in interface Parameterized

Overrides:

getParameterDescriptors in class AbstractMathTransform2D

Returns:

The parameter descriptors for this math transform, or null.

See Also:

OperationMethod.getParameters()

transform

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

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

Specified by:

transform in class UnitaryProjection

Parameters:

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

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). Ordinates will be in a dimensionless unit, as a linear distance on a unit sphere or ellipse.

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

Throws:

ProjectionException - if the point can't be converted.

transform

public void transform(double[] srcPts,
                      int srcOff,
                      double[] dstPts,
                      int dstOff,
                      int numPts)
               throws TransformException

Converts a list of coordinate point ordinal values.

Note: We override the super-class method only as an optimization in the special case where the target coordinates are written at the same locations than the source coordinates. In such case, we can take advantage of the fact that the φ value is not modified by the unitary Equirectangular projection.

Specified by:

transform in interface MathTransform

Overrides:

transform in class UnitaryProjection

Parameters:

srcPts - The array containing the source point coordinates.

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

dstPts - The array into which the converted point coordinates are returned. May be the same than srcPts.

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

numPts - The number of point objects to be converted.

Throws:

TransformException - if a point can't be converted.

inverseTransform

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

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

Specified by:

inverseTransform in class UnitaryProjection

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). Ordinates 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't be converted.

isIdentity

public boolean isIdentity()

Returns true if this unitary projection is the identity transform. The kernel of an equirectangular projection is an identity transform if it doesn't performs longitude rolling.

Specified by:

isIdentity in interface MathTransform

Overrides:

isIdentity in class AbstractMathTransform