org.geotools.referencing.operation.transform

Class ConcatenatedTransform

Object

Formattable

AbstractMathTransform

ConcatenatedTransform

All Implemented Interfaces:

Serializable, MathTransform

public class ConcatenatedTransform
extends AbstractMathTransform
implements Serializable

Base class for concatenated transform. Concatenated transforms are serializable if all their step transforms are serializables.

Since:

2.0

Author:

Martin Desruisseaux (IRD)

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class AbstractMathTransform

AbstractMathTransform.Inverse

Field Summary

Fields

Modifier and Type	Field and Description
MathTransform	transform1 The first math transform.
MathTransform	transform2 The second math transform.

Fields inherited from class Formattable

SINGLE_LINE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ConcatenatedTransform(MathTransform transform1, MathTransform transform2) Constructs a concatenated transform.

Method Summary

Modifier and Type	Method and Description
static MathTransform	create(MathTransform tr1, MathTransform tr2) Constructs a concatenated transform.
Matrix	derivative(DirectPosition point) Gets the derivative of this transform at a point.
Matrix	derivative(Point2D point) Gets the derivative of this transform at a point.
boolean	equals(Object object) Compares the specified object with this math transform for equality.
protected String	formatWKT(Formatter formatter) Format the inner part of a Well Known Text (WKT) element.
int	getSourceDimensions() Gets the dimension of input points.
int	getStepCount() Returns the number of math transform steps performed by this concatenated transform.
int	getTargetDimensions() Gets the dimension of output points.
int	hashCode() Returns a hash value for this transform.
MathTransform	inverse() Creates the inverse transform of this object.
boolean	isIdentity() Tests whether this transform does not move any points.
DirectPosition	transform(DirectPosition ptSrc, DirectPosition ptDst) Transforms the specified ptSrc and stores the result in ptDst.
void	transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts) Transforms a list of coordinate point ordinal values.
void	transform(float[] srcPts, int srcOff, float[] dstPts, int dstOff, int numPts) Transforms a list of coordinate point ordinal values.

Methods inherited from class AbstractMathTransform

createTransformedShape, ensureNonNull, getName, getParameterDescriptors, getParameterValues, needCopy, normalizeAngle, rollLongitude, 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

toWKT

Field Detail

transform1

public final MathTransform transform1

The first math transform.

transform2

public final MathTransform transform2

The second math transform.

Constructor Detail

ConcatenatedTransform

protected ConcatenatedTransform(MathTransform transform1,
                                MathTransform transform2)

Constructs a concatenated transform. This constructor is for subclasses only. To create a concatenated transform, use the factory method create(org.opengis.referencing.operation.MathTransform, org.opengis.referencing.operation.MathTransform) instead.

Parameters:

transform1 - The first math transform.

transform2 - The second math transform.

Method Detail

create

public static MathTransform create(MathTransform tr1,
                                   MathTransform tr2)

Constructs a concatenated transform. This factory method checks for step transforms dimension. The returned transform will implements MathTransform2D if source and target dimensions are equal to 2. Likewise, it will implements MathTransform1D if source and target dimensions are equal to 1. MathTransform implementations are available in two version: direct and non-direct. The "non-direct" version use an intermediate buffer when performing transformations; they are slower and consume more memory. They are used only as a fallback when a "direct" version can't be created.

Parameters:

tr1 - The first math transform.

tr2 - The second math transform.

Returns:

The concatenated transform.

getSourceDimensions

public final int getSourceDimensions()

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 final int getTargetDimensions()

Gets the dimension of output points.

Specified by:

getTargetDimensions in interface MathTransform

Specified by:

getTargetDimensions in class AbstractMathTransform

Returns:

The dimension of output points.

getStepCount

public final int getStepCount()

Returns the number of math transform steps performed by this concatenated transform.

Returns:

The number of transform steps.

Since:

2.5

transform

public DirectPosition transform(DirectPosition ptSrc,
                                DirectPosition ptDst)
                         throws TransformException

Transforms the specified ptSrc and stores the result in ptDst.

Specified by:

transform in interface MathTransform

Overrides:

transform in class AbstractMathTransform

Parameters:

ptSrc - the specified coordinate point to be transformed.

ptDst - the specified coordinate point that stores the result of transforming ptSrc, or null.

Returns:

the coordinate point after transforming ptSrc and storing the result in ptDst, or a newly created point if ptDst was null.

Throws:

TransformException - if the point can't be transformed.

transform

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

Transforms a list of coordinate point ordinal values. The source points are first transformed by transform1, then the intermediate points are transformed by transform2. The transformations are performed without intermediate buffer if it can be avoided.

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 a point can't be transformed. Some implementations will stop at the first failure, wile some other implementations will fill the untransformable points with NaN values, continue and throw the exception only at end. Implementations that fall in the later case should set the last completed transform to this.

transform

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

Transforms a list of coordinate point ordinal values. The source points are first copied in a temporary array of type double[], transformed by transform1 first, then by transform2 and finally the result is casted to float primitive type and stored in the destination array. The use of double primitive type for intermediate results is necesssary for reducing rounding errors.

Specified by:

transform in interface MathTransform

Overrides:

transform in class AbstractMathTransform

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 a point can't be transformed. Some implementations will stop at the first failure, wile some other implementations will fill the untransformable points with NaN values, continue and throw the exception only at end. Implementations that fall in the later case should set the last completed transform to this.

inverse

public MathTransform inverse()
                      throws NoninvertibleTransformException

Creates the inverse transform of this object.

Specified by:

inverse in interface MathTransform

Overrides:

inverse in class AbstractMathTransform

Returns:

The inverse transform.

Throws:

NoninvertibleTransformException - if the transform can't be inversed.

derivative

public Matrix derivative(Point2D point)
                  throws TransformException

Gets the derivative of this transform at a point. This method delegates to the derivative(DirectPosition) method because the transformation steps transform1 and transform2 may not be instances of 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:

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

See Also:

MathTransform2D.derivative(Point2D)

derivative

public Matrix derivative(DirectPosition point)
                  throws TransformException

Gets the derivative of this transform at a point.

Specified by:

derivative in interface MathTransform

Overrides:

derivative in class AbstractMathTransform

Parameters:

point - The coordinate point where to evaluate the derivative.

Returns:

The derivative at the specified point (never null).

Throws:

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

isIdentity

public final boolean isIdentity()

Tests whether this transform does not move any points. Default implementation check if the two transforms are identity.

Specified by:

isIdentity in interface MathTransform

Overrides:

isIdentity in class AbstractMathTransform

Returns:

true if this MathTransform is an identity transform; false otherwise.

hashCode

public final int hashCode()

Returns a hash value for this transform.

Overrides:

hashCode in class AbstractMathTransform

equals

public final boolean equals(Object object)

Compares the specified object with this math transform for equality.

Overrides:

equals in class AbstractMathTransform

Parameters:

object - The object to compare with this transform.

Returns:

true if the given object is a transform of the same class and if, given identical source position, the transformed position would be the equals.

formatWKT

protected String formatWKT(Formatter formatter)

Format the inner part of a Well Known Text (WKT) element.

Overrides:

formatWKT in class AbstractMathTransform

Parameters:

formatter - The formatter to use.

Returns:

The WKT element name.

See Also:

Formattable.toWKT(), Formattable.toString()