org.geotoolkit.referencing.operation.transform
Class LinearTransform1D

Object
  FormattableObject
      AbstractMathTransform
          AbstractMathTransform1D
              LinearTransform1D

All Implemented Interfaces:

Serializable, Formattable, LinearTransform, Parameterized, LenientComparable, MathTransform, MathTransform1D

@Immutable
public class LinearTransform1D
extends AbstractMathTransform1D
implements LinearTransform, Serializable

A one dimensional, linear transform. Input values x are converted into output values y using the following equation:

y = x × scale + offset

This class is the same as a 2×2 affine transform. However, this specialized LinearTransform1D class is faster. This kind of transform is extensively used by GridCoverage2D.

See any of the following providers for a list of programmatic parameters:

• Affine

Since:

2.0

Version:

3.18

Author:

Martin Desruisseaux (IRD, Geomatys)

See Also:

LogarithmicTransform1D, ExponentialTransform1D, Serialized Form

Module:

referencing/geotk-referencing (download)

View source code for this class

Nested Class Summary

Nested classes/interfaces inherited from class AbstractMathTransform

AbstractMathTransform.Inverse

Field Summary

static LinearTransform1D	IDENTITY The identity transform.
double	offset The value to add to input values.
double	scale The value which is multiplied to input values.

Fields inherited from class FormattableObject

EPSG, GEOTIFF, INTERNAL, OGC, SINGLE_LINE

Constructor Summary

protected

LinearTransform1D(double scale, double offset) Constructs a new linear transform.

Method Summary

protected int	computeHashCode() Computes a hash value for this transform.
static LinearTransform1D	create(double scale, double offset) Constructs a new linear transform.
Matrix	derivative(DirectPosition point) Gets the derivative of this transform at a point.
double	derivative(double value) Gets the derivative of this function at a value.
boolean	equals(Object object, ComparisonMode mode) Compares the specified object with this math transform for equality.
Matrix	getMatrix() Returns this transform as an affine transform matrix.
ParameterDescriptorGroup	getParameterDescriptors() Returns the parameter descriptors for this math transform.
ParameterValueGroup	getParameterValues() Returns the matrix elements as a group of parameters values.
MathTransform1D	inverse() Creates the inverse transform of this object.
boolean	isIdentity() Tests whether this transform does not move any points.
boolean	isIdentity(double tolerance) Tests whether this transform does not move any points by using the provided tolerance.
double	transform(double value) Transforms the specified value.
protected void	transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) Transforms a single coordinate in a list of ordinal values.
void	transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts) Transforms many coordinates in a list of ordinal values.
void	transform(double[] srcPts, int srcOff, float[] dstPts, int dstOff, int numPts) Transforms many coordinates in a list of ordinal values.
void	transform(float[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts) Transforms many coordinates in a list of ordinal values.
void	transform(float[] srcPts, int srcOff, float[] dstPts, int dstOff, int numPts) Transforms many coordinates in a list of ordinal values.

Methods inherited from class AbstractMathTransform1D

getSourceDimensions, getTargetDimensions

Methods inherited from class AbstractMathTransform

createTransformedShape, derivative, 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 MathTransform

getSourceDimensions, getTargetDimensions, toWKT, transform

Methods inherited from interface LenientComparable

equals

Field Detail

IDENTITY

public static final LinearTransform1D IDENTITY

The identity transform.

scale

public final double scale

The value which is multiplied to input values.

offset

public final double offset

The value to add to input values.

Constructor Detail

LinearTransform1D

protected LinearTransform1D(double scale,
                            double offset)

Constructs a new linear transform. This constructor is provided for subclasses only. Instances should be created using the factory method, which may returns optimized implementations for some particular argument values.

Parameters:

scale - The scale term in the linear equation.

offset - The offset term in the linear equation.

Method Detail

create

public static LinearTransform1D create(double scale,
                                       double offset)

Constructs a new linear transform.

Parameters:

scale - The scale term in the linear equation.

offset - The offset term in the linear equation.

Returns:

The linear transform for the given scale and offset.

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 matrix elements as a group of parameters values. The number of parameters depends on the matrix size. Only matrix elements different from their default value will be included in this group.

Specified by:

getParameterValues in interface Parameterized

Overrides:

getParameterValues in class AbstractMathTransform

Returns:

A copy of the parameter values for this math transform.

See Also:

SingleOperation.getParameterValues()

getMatrix

public Matrix getMatrix()

Returns this transform as an affine transform matrix.

Specified by:

getMatrix in interface LinearTransform

Returns:

A copy of the underlying matrix.

inverse

public MathTransform1D inverse()
                        throws NoninvertibleTransformException

Creates the inverse transform of this object.

Specified by:

inverse in interface MathTransform

Specified by:

inverse in interface MathTransform1D

Overrides:

inverse in class AbstractMathTransform1D

Throws:

NoninvertibleTransformException

isIdentity

public boolean isIdentity()

Tests whether this transform does not move any points.

Specified by:

isIdentity in interface MathTransform

Overrides:

isIdentity in class AbstractMathTransform

isIdentity

public boolean isIdentity(double tolerance)

Tests whether this transform does not move any points by using the provided tolerance.

Specified by:

isIdentity in interface LinearTransform

Parameters:

tolerance - The tolerance factor.

Returns:

true if this transform is the identity one

Since:

2.3.1

See Also:

XMatrix.isIdentity(double)

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 AbstractMathTransform1D

Parameters:

point - Ignored for a linear transform. Can be null.

Returns:

The derivative at the given point.

Throws:

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

derivative

public double derivative(double value)

Gets the derivative of this function at a value.

Specified by:

derivative in interface MathTransform1D

Parameters:

value - Ignored for a linear transform. Can be NaN.

Returns:

The derivative at the given point.

transform

public double transform(double value)

Transforms the specified value.

Specified by:

transform in interface MathTransform1D

transform

protected void transform(double[] srcPts,
                         int srcOff,
                         double[] dstPts,
                         int dstOff)

Transforms a single coordinate in a list of ordinal values.

Overrides:

transform in class AbstractMathTransform1D

Parameters:

srcPts - The array containing the source point coordinates.

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

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

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

transform

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

Transforms many coordinates in a list of ordinal values.

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.

transform

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

Transforms many coordinates in a list of ordinal values.

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.

transform

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

Transforms many coordinates in a list of ordinal values.

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.

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.

transform

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

Transforms many coordinates in a list of ordinal values.

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.

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.

computeHashCode

protected int computeHashCode()

Computes a hash value for this transform. This method is invoked by AbstractMathTransform.hashCode() when first needed.

Overrides:

computeHashCode in class AbstractMathTransform

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 specified object with this math transform for equality. The default implementation returns true if the following conditions are meet:

• object is an instance of the same class than this. We require the same class because there is no interface for the various kinds of transform.
• The parameter descriptors are equal according the given comparison mode.

The parameter values are not compared because subclasses can typically compare those values more efficiently by accessing to their member fields.

Specified by:

equals in interface LinearTransform

Specified by:

equals in interface LenientComparable

Overrides:

equals in class AbstractMathTransform

Parameters:

object - The object to compare with this transform.

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

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.