org.geotoolkit.referencing.operation.projection
Class Krovak

Object
  FormattableObject
      AbstractMathTransform
          AbstractMathTransform2D
              UnitaryProjection
                  Krovak

All Implemented Interfaces:

Serializable, Formattable, Parameterized, LenientComparable, MathTransform, MathTransform2D

@Immutable
public class Krovak
extends UnitaryProjection

Krovak Oblique Conformal Conic projection (EPSG code 9819). See the Krovak on POSC for an overview. See any of the following providers for a list of programmatic parameters:

• Krovak

Description
This projection is used in the Czech Republic and Slovakia under the name "Krovak" projection. The geographic coordinates on the ellipsoid are first reduced to conformal coordinates on the conformal (Gaussian) sphere. These spherical coordinates are then projected onto the oblique cone and converted to grid coordinates. The pseudo standard parallel is defined on the conformal sphere after its rotation, to obtain the oblique aspect of the projection. It is then the parallel on this sphere at which the map projection is true to scale; on the ellipsoid it maps as a complex curve.

The compulsory parameters are just the ellipsoid characteristics. All other parameters are optional and have defaults to match the common usage with Krovak projection.

Projected CRS using the Krovak projection are usually defined with (southing, westing) axis orientations. ESRI uses those orientations by default. However in Geotk, every projection must have (easting, northing) orientations - axis reversal are handled by the concatenation of affine transforms. Consequently in order to get the usual axis order, a Krovak projected CRS must defines axis order explicitly (as required by the OGC standard) like in the example below:

PROJCS["S-JTSK (Ferro) / Krovak",
    GEOCS[...],
  PROJECTION["Krovak"],
  PARAMETER["semi_major", 6377397.155],
  PARAMETER["semi_minor", 6356078.963],
  UNIT["metre", 1],
  AXIS["y", SOUTH],
  AXIS["x", WEST]]

The default Krovak projection implemented by this class - having (easting, northing) axis orientations - is cold Krovak GIS version.

References

• Proj-4.4.7 available at www.remotesensing.org/proj
  Relevant files is: PJ_krovak.c
• "Coordinate Conversions and Transformations including Formulas" available at, http://www.remotesensing.org/geotiff/proj_list/guid7.html

Since:

2.4

Version:

3.20

Author:

Jan Jezek (HSRS), Martin Desruisseaux (IRD, Geomatys), Rémi Maréchal (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

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

Method Summary

protected int	computeHashCode() Computes a hash code value for this unitary projection.
static MathTransform2D	create(ParameterDescriptorGroup descriptor, ParameterValueGroup values) Creates a Krovak projection from the given parameters.
boolean	equals(Object object, ComparisonMode mode) Compares the given object with this transform for equivalence.
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).
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 (linear distance on a unit sphere).

Methods inherited from class UnitaryProjection

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

Methods inherited from class AbstractMathTransform2D

getParameterDescriptors, getSourceDimensions, getTargetDimensions, transform

Methods inherited from class AbstractMathTransform

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

Methods inherited from class FormattableObject

getDefaultIndentation, print, setDefaultIndentation, toString, toWKT, 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, isIdentity, toWKT, transform, transform, transform, transform, transform

Constructor Detail

Krovak

protected Krovak(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 a Krovak projection from the given parameters. The descriptor argument is usually Krovak.PARAMETERS, but is not restricted to. If a different descriptor is supplied, it is user's responsibility to ensure that it is suitable to a Krovak projection.

Parameters:

descriptor - Typically Krovak.PARAMETERS.

values - The parameter values of the projection to create.

Returns:

The map projection.

Since:

3.00

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 (linear distance on a unit sphere). In addition, opportunistically computes the projection derivative if derivate is true.

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 expressed 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.

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 point can't be converted.

Since:

3.20 (derived from 3.00)

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

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.

computeHashCode

protected int computeHashCode()

Computes a hash code value for this unitary projection. The default implementation computes a value from the parameters given at construction time.

Overrides:

computeHashCode in class UnitaryProjection

Returns:

The hash code value. This value may change between different execution of the Geotk library.

equals

public boolean equals(Object object,
                      ComparisonMode mode)

Compares the given object with this transform for equivalence.

Specified by:

equals in interface LenientComparable

Overrides:

equals in class UnitaryProjection

Parameters:

object - The object to compare with this unitary projection for equivalence.

mode - The strictness level of the comparison. Default to STRICT.

Returns:

true if the given object is equivalent to this unitary projection.

See Also:

Utilities.deepEquals(Object, Object, ComparisonMode)