Package org.geotools.referencing.operation.transform

Class NTv2Transform

Object

Formattable

AbstractMathTransform

NTv2Transform

All Implemented Interfaces:

Serializable, MathTransform, MathTransform2D

public class NTv2Transform
extends AbstractMathTransform
implements MathTransform2D, Serializable

The "NTv2" coordinate transformation method (EPSG:9615).

This transformation depends on an external resource (the NTv2 grid file). If the file is not available, a recoverable NoSuchIdentifierException will be thrown on instantiation.

Author:

Oscar Fonts

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	NTv2Transform.Provider	The NTv2Transform provider.

Field Summary

Fields

Modifier and Type	Field	Description
protected static final Logger	LOGGER	Logger

Fields inherited from class Formattable

SINGLE_LINE

Constructor Summary

Constructors

Constructor	Description
NTv2Transform(URI file)	Constructs a NTv2Transform from the specified grid shift file.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object object)	Compares the specified object with this one for equality.
ParameterValueGroup	getParameterValues()	Returns the parameter values for this math transform.
int	getSourceDimensions()	Gets the dimension of input points.
int	getTargetDimensions()	Gets the dimension of output points.
int	hashCode()	Returns a hash value for this transform.
MathTransform2D	inverse()	Returns the inverse of this transform.
void	inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts)	Inverse transform.
void	transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts)	Transforms a list of coordinate point ordinal values.

Methods inherited from class AbstractMathTransform

createTransformedShape, derivative, derivative, ensureNonNull, formatWKT, getName, getParameterDescriptors, isIdentity, needCopy, normalizeAngle, rollLongitude, transform, transform, transform, transform, transform

Methods inherited from class Formattable

cleanupThreadLocals, toString, toWKT, toWKT, toWKT, 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

Methods inherited from interface MathTransform2D

createTransformedShape, derivative, transform

Field Details

LOGGER

protected static final Logger LOGGER

Logger

Constructor Details

NTv2Transform

public NTv2Transform(URI file)
              throws NoSuchIdentifierException

Constructs a NTv2Transform from the specified grid shift file.

This constructor checks for grid shift file availability, but doesn't actually load the full grid into memory to preserve resources.

Parameters:

file - NTv2 grid file name

Throws:

NoSuchIdentifierException - if the grid is not available.

Method Details

hashCode

public int hashCode()

Returns a hash value for this transform.

Overrides:

hashCode in class AbstractMathTransform

equals

public boolean equals(Object object)

Compares the specified object with this one for equality. Checks if object is this same instance, or a NTv2Transform with the same parameter values.

Overrides:

equals in class AbstractMathTransform

Parameters:

object - The object to compare with this transform.

Returns:

true if the given object is this, or a NTv2Transform with same parameter values, which would mean that given identical source position, the transformed position would be the same.

inverse

public MathTransform2D inverse()

Returns the inverse of this transform.

Specified by:

inverse in interface MathTransform

Specified by:

inverse in interface MathTransform2D

Overrides:

inverse in class AbstractMathTransform

Returns:

the inverse of this transform

transform

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

Transforms a list of coordinate point ordinal values. This method is provided for efficiently transforming many points. The supplied array of ordinal values will contain packed ordinal values. For example, if the source dimension is 3, then the ordinals will be packed in this order: (x₀,y₀,z₀,

x₁,y₁,z₁ ...).

Specified by:

transform in interface MathTransform

Parameters:

srcPts - the array containing the source point coordinates.

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

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

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

numPts - the number of point objects to be transformed.

Throws:

TransformException - if an IO error occurs reading the grid file.

inverseTransform

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

Inverse transform. See transform(double[], int, double[], int, int)

Parameters:

srcPts - the array containing the source point coordinates.

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

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

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

numPts - the number of point objects to be transformed.

Throws:

TransformException - if an IO error occurs reading the grid file.

getSourceDimensions

public int getSourceDimensions()

Description copied from class: AbstractMathTransform

Gets the dimension of input points.

Specified by:

getSourceDimensions in interface MathTransform

Specified by:

getSourceDimensions in class AbstractMathTransform

Returns:

The dimension of input points.

getTargetDimensions

public int getTargetDimensions()

Description copied from class: AbstractMathTransform

Gets the dimension of output points.

Specified by:

getTargetDimensions in interface MathTransform

Specified by:

getTargetDimensions in class AbstractMathTransform

Returns:

The dimension of output points.

getParameterValues

public ParameterValueGroup getParameterValues()

Returns the parameter values for this math transform.

Overrides:

getParameterValues in class AbstractMathTransform

Returns:

A copy of the parameter values for this math transform.

See Also:

• Operation.getParameterValues()