org.geotoolkit.referencing.operation.transform
Class NTv2Transform

Object
  FormattableObject
      AbstractMathTransform
          GridTransform
              GridTransform2D
                  NTv2Transform

All Implemented Interfaces:

Serializable, Formattable, Parameterized, LenientComparable, MathTransform, MathTransform2D

public class NTv2Transform
extends GridTransform2D

Transform based on a NTv2 grid (EPSG code 9615). See any of the following providers for a list of programmatic parameters:

• NTv2

Description
This is a geodetic transformation simular to NadconTransform, operating on geographic coordinate differences by bi-linear interpolation.

Note: The original NTv2 grids expect longitudes to be positive west. However this class performs the sign reversal by itself, so inputs given to NTv2Transform have longitudes positive east.

Since:

3.12

Version:

3.12

Author:

Simon Reynard (Geomatys)

See Also:

List of some NTv2 files, Serialized Form

Module:

referencing/geotk-referencing (download)

View source code for this class

Field Summary

static String

RGF93 The file name of RGF93 grid, which is "ntf_r93.gsb".

Fields inherited from class GridTransform

grid, height, width

Fields inherited from class FormattableObject

EPSG, GEOTIFF, INTERNAL, OGC, SINGLE_LINE

Constructor Summary

NTv2Transform(String gridFile)
Constructs a grid from the specified shift file.

Method Summary

ParameterDescriptorGroup	getParameterDescriptors() Returns the parameter descriptors for this math transform.
ParameterValueGroup	getParameterValues() Returns the parameter values for this math transform.

Methods inherited from class GridTransform2D

derivative, inverse

Methods inherited from class GridTransform

computeHashCode, create, create, create, derivative, equals, getSourceDimensions, getTargetDimensions, isIdentity, transform, transform, transform, transform, transform

Methods inherited from class AbstractMathTransform

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

Methods inherited from interface MathTransform

derivative, getSourceDimensions, getTargetDimensions, isIdentity, toWKT, transform, transform, transform, transform, transform

Field Detail

RGF93

public static final String RGF93

The file name of RGF93 grid, which is "ntf_r93.gsb". This grid can be downloaded from http://lambert93.ign.fr/.

See Also:

Constant Field Values

Constructor Detail

NTv2Transform

public NTv2Transform(String gridFile)
              throws FactoryException

Constructs a grid from the specified shift file. The argument may be a file path and name, or just the file name. It is resolved as below:

• If the argument is a URL or absolute file, then it is used directly.
• Otherwise if the argument is a single filename with no parent directory, and if the file is found in a org/geotoolkit/referencing/operation/transform/NTv2 directory on the classpath, then that later file is used.
• Otherwise (i.e. the file is relative and not presents on the classpath), prepend the grid location set by the user, if any. This location can be set by the geotk-setup module, which can also download and install the data.

Parameters:

gridFile - Path (optional) and name to the longitude difference file. This will typically have a ".gsb" file extention.

Throws:

FactoryException - If there is an error reading the grid file.

Method Detail

getParameterDescriptors

public ParameterDescriptorGroup getParameterDescriptors()

Returns the parameter descriptors for this math transform.

Specified by:

getParameterDescriptors in interface Parameterized

Overrides:

getParameterDescriptors in class AbstractMathTransform

Returns:

The parameter descriptors for this math transform, or null.

See Also:

OperationMethod.getParameters()

getParameterValues

public ParameterValueGroup getParameterValues()

Returns the parameter values for this math transform.

Specified by:

getParameterValues in interface Parameterized

Overrides:

getParameterValues in class AbstractMathTransform

Returns:

A copy of the parameter values for this math transform, or null. Since this method returns a copy of the parameter values, any change to a value will have no effect on this math transform.

See Also:

SingleOperation.getParameterValues()