org.geotoolkit.referencing.operation.projection
Class LambertConformal

Object
  FormattableObject
      AbstractMathTransform
          AbstractMathTransform2D
              UnitaryProjection
                  LambertConformal

All Implemented Interfaces:

Serializable, Formattable, Parameterized, LenientComparable, MathTransform, MathTransform2D

@Immutable
public class LambertConformal
extends UnitaryProjection

Lambert Conical Conformal Projection (EPSG codes 9801, 9802, 9803). See the Lambert conformal conic projection on MathWorld for an overview. See any of the following providers for a list of programmatic parameters:

• LambertConformal1SP
• LambertConformal2SP
• LambertConformal2SP.Belgium
• LambertConformal2SP.ESRI

Description
Areas and shapes are deformed as one moves away from standard parallels. The angles are true in a limited area. This projection is used for the charts of North America and some European countries.

This implementation provides transforms for four cases of the lambert conic conformal projection:

• Lambert_Conformal_Conic_1SP (EPSG code 9801)
• Lambert_Conformal_Conic_2SP (EPSG code 9802)
• Lambert_Conic_Conformal_2SP_Belgium (EPSG code 9803)
• Lambert_Conformal_Conic - An alias for the ESRI 2SP case that includes a "scale_factor" parameter

For the 1SP case the latitude of origin is used as the standard parallel (SP). To use 1SP with a latitude of origin different from the SP, use the 2SP and set the SP1 to the single SP. The standard_parallel_2" parameter is optional and will be given the same value as "standard_parallel_1" if not set (creating a 1 standard parallel projection).

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, Version 19.

Since:

1.0

Version:

3.18

Author:

Martin Desruisseaux (MPO, IRD, Geomatys), André Gosselin (MPO), Rueben Schulz (UBC)

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

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

Method Summary

static MathTransform2D	create(ParameterDescriptorGroup descriptor, ParameterValueGroup values) Creates a Lambert projection from the given parameters.
Matrix	derivative(Point2D point) Gets the derivative of this transform at a point.
boolean	equals(Object object, ComparisonMode mode) Compares the given object with this transform for equivalence.
ParameterDescriptorGroup	getParameterDescriptors() Returns the parameter descriptors for this unitary projection.
ParameterValueGroup	getParameterValues() Returns a copy of the parameter values for this 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).
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).

Methods inherited from class UnitaryProjection

computeHashCode, finish, getUnmarshalledParameters, inverse, resetWarnings, rollLongitude, transform, unrollLongitude

Methods inherited from class AbstractMathTransform2D

getSourceDimensions, getTargetDimensions, transform

Methods inherited from class AbstractMathTransform

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

Methods inherited from interface MathTransform

derivative, isIdentity, toWKT, transform, transform, transform, transform

Constructor Detail

LambertConformal

protected LambertConformal(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 Lambert projection from the given parameters. The descriptor argument is usually one of the PARAMETERS constants defined in LambertConformal1SP or LambertConformal2SP, but is not restricted to. If a different descriptor is supplied, it is user's responsibility to ensure that it is suitable to a Lambert Conformal projection.

Parameters:

descriptor - Typically one of LambertConformal1SP.PARAMETERS or LambertConformal2SP.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. Consequently the current implementation returns the descriptor of LambertConformal2SP in all cases, because the 1SP case is implemented as 2SP with both standard parallels set to the latitude of origin.

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()

getParameterValues

public ParameterValueGroup getParameterValues()

Returns a copy of the parameter values for this projection. The default implementation returns the parameters defined in the super-class, with the addition of standard parallels. No other parameters are set, because the above ones are the only significant ones for this unitary projection.

Specified by:

getParameterValues in interface Parameterized

Overrides:

getParameterValues in class UnitaryProjection

Returns:

A copy of the parameter values for this unitary projection.

See Also:

SingleOperation.getParameterValues()

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.

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.

derivative

public Matrix derivative(Point2D point)
                  throws ProjectionException

Gets the derivative of this transform at a point. The current implementation is derived from the spherical formulas.

Specified by:

derivative in interface MathTransform2D

Overrides:

derivative in class AbstractMathTransform

Parameters:

point - The coordinate point where to evaluate the derivative.

Returns:

The derivative at the specified point as a 2×2 matrix.

Throws:

ProjectionException - if the derivative can't be evaluated at the specified point.

Since:

3.14

See Also:

MathTransform2D.derivative(Point2D)

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.