org.geotools.referencing.operation.transform
Class LinearTransform1D

java.lang.Object
  org.geotools.referencing.wkt.Formattable
      org.geotools.referencing.operation.transform.AbstractMathTransform
          org.geotools.referencing.operation.transform.LinearTransform1D

All Implemented Interfaces:

LinearTransform, org.opengis.referencing.operation.MathTransform, org.opengis.referencing.operation.MathTransform1D, java.io.Serializable

public class LinearTransform1D

extends AbstractMathTransform

implements org.opengis.referencing.operation.MathTransform1D, LinearTransform, java.io.Serializable

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

y = offset + scale×x

This class is the same as a 2×2 affine transform. However, this specialized class is faster. It is defined there because extensively used by GridCoverage2D.

Since:

2.0

Version:

$Id: LinearTransform1D.java 17672 2006-01-19 00:25:55Z desruisseaux $

Author:

Martin Desruisseaux

See Also:

LogarithmicTransform1D, ExponentialTransform1D, Serialized Form

Nested Class Summary

Nested classes inherited from class org.geotools.referencing.operation.transform.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.

Constructor Summary

protected

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

Method Summary

static LinearTransform1D	create(double scale, double offset) Constructs a new linear transform.
org.opengis.referencing.operation.Matrix	derivative(org.opengis.spatialschema.geometry.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(java.lang.Object object) Compares the specified object with this math transform for equality.
org.opengis.referencing.operation.Matrix	getMatrix() Returns this transform as an affine transform matrix.
org.opengis.parameter.ParameterDescriptorGroup	getParameterDescriptors() Returns the parameter descriptors for this math transform.
org.opengis.parameter.ParameterValueGroup	getParameterValues() Returns the matrix elements as a group of parameters values.
int	getSourceDimensions() Gets the dimension of input points, which is 1.
int	getTargetDimensions() Gets the dimension of output points, which is 1.
int	hashCode() Returns a hash value for this transform.
org.opengis.referencing.operation.MathTransform	inverse() Creates the inverse transform of this object.
boolean	isIdentity() Tests whether this transform does not move any points.
double	transform(double value) Transforms the specified value.
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 org.geotools.referencing.operation.transform.AbstractMathTransform

createTransformedShape, derivative, ensureNonNull, formatWKT, getDimSource, getDimTarget, needCopy, rollLongitude, transform, transform

Methods inherited from class org.geotools.referencing.wkt.Formattable

toString, toWKT, toWKT, toWKT

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.opengis.referencing.operation.MathTransform

toWKT, transform

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 term in the linear equation.

offset - The term in the linear equation.

Method Detail

create

public static LinearTransform1D create(double scale,
                                       double offset)

Constructs a new linear transform.

Parameters:

scale - The term in the linear equation.

offset - The term in the linear equation.

getParameterDescriptors

public org.opengis.parameter.ParameterDescriptorGroup getParameterDescriptors()

Returns the parameter descriptors for this math transform.

Overrides:

getParameterDescriptors in class AbstractMathTransform

Returns:

The parameter descriptors for this math transform, or .

See Also:

OperationMethod.getParameters()

getParameterValues

public org.opengis.parameter.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.

Overrides:

getParameterValues in class AbstractMathTransform

Returns:

A copy of the parameter values for this math transform.

See Also:

Operation.getParameterValues()

getSourceDimensions

public int getSourceDimensions()

Gets the dimension of input points, which is 1.

Specified by:

getSourceDimensions in interface org.opengis.referencing.operation.MathTransform

Specified by:

getSourceDimensions in class AbstractMathTransform

getTargetDimensions

public int getTargetDimensions()

Gets the dimension of output points, which is 1.

Specified by:

getTargetDimensions in interface org.opengis.referencing.operation.MathTransform

Specified by:

getTargetDimensions in class AbstractMathTransform

getMatrix

public org.opengis.referencing.operation.Matrix getMatrix()

Returns this transform as an affine transform matrix.

Specified by:

getMatrix in interface LinearTransform

inverse

public org.opengis.referencing.operation.MathTransform inverse()
                                                        throws org.opengis.referencing.operation.NoninvertibleTransformException

Creates the inverse transform of this object.

Specified by:

inverse in interface org.opengis.referencing.operation.MathTransform

Overrides:

inverse in class AbstractMathTransform

Throws:

org.opengis.referencing.operation.NoninvertibleTransformException

isIdentity

public boolean isIdentity()

Tests whether this transform does not move any points.

Specified by:

isIdentity in interface org.opengis.referencing.operation.MathTransform

Overrides:

isIdentity in class AbstractMathTransform

derivative

public org.opengis.referencing.operation.Matrix derivative(org.opengis.spatialschema.geometry.DirectPosition point)
                                                    throws org.opengis.referencing.operation.TransformException

Gets the derivative of this transform at a point. This implementation is different from the default AbstractMathTransform.derivative(java.awt.geom.Point2D) implementation in that no coordinate point is required and Double.NaN may be a legal output value for some users.

Specified by:

derivative in interface org.opengis.referencing.operation.MathTransform

Overrides:

derivative in class AbstractMathTransform

Parameters:

point - The coordinate point where to evaluate the derivative.

Returns:

The derivative at the specified point (never ).

Throws:

org.opengis.referencing.operation.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 org.opengis.referencing.operation.MathTransform1D

transform

public double transform(double value)

Transforms the specified value.

Specified by:

transform in interface org.opengis.referencing.operation.MathTransform1D

transform

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

Transforms a list of coordinate point ordinal values.

Specified by:

transform in interface org.opengis.referencing.operation.MathTransform

Overrides:

transform in class AbstractMathTransform

transform

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

Transforms a list of coordinate point ordinal values.

Specified by:

transform in interface org.opengis.referencing.operation.MathTransform

hashCode

public int hashCode()

Returns a hash value for this transform. This value need not remain consistent between different implementations of the same class.

Overrides:

hashCode in class AbstractMathTransform

equals

public boolean equals(java.lang.Object object)

Compares the specified object with this math transform for equality.

Overrides:

equals in class AbstractMathTransform