Package org.geotools.referencing.operation.transform

Class LinearTransform1D

Object
Formattable
AbstractMathTransform
LinearTransform1D
All Implemented Interfaces:
Serializable, MathTransform, MathTransform1D, LinearTransform
public class LinearTransform1D extends AbstractMathTransform implements MathTransform1D, LinearTransform, 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 LinearTransform1D class is faster. It is defined there because extensively used by GridCoverage2D.

Since:
2.0
Author:
Martin Desruisseaux (IRD)
See Also:

  • Field Details

    • 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 Details

    • 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 Details

    • 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.

    • getParameterDescriptors

      public ParameterDescriptorGroup getParameterDescriptors()
      Returns the parameter descriptors for this math transform.
      Overrides:
      getParameterDescriptors in class AbstractMathTransform
      Returns:
      The parameter descriptors for this math transform, or null.
      See Also:

    • 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.
      Overrides:
      getParameterValues in class AbstractMathTransform
      Returns:
      A copy of the parameter values for this math transform.
      See Also:

    • getSourceDimensions

      public int getSourceDimensions()
      Gets the dimension of input points, which is 1.
      Specified by:
      getSourceDimensions in interface MathTransform
      Specified by:
      getSourceDimensions in class AbstractMathTransform
      Returns:
      The dimension of input points.

    • getTargetDimensions

      public int getTargetDimensions()
      Gets the dimension of output points, which is 1.
      Specified by:
      getTargetDimensions in interface MathTransform
      Specified by:
      getTargetDimensions in class AbstractMathTransform
      Returns:
      The dimension of output points.

    • 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 AbstractMathTransform
      Returns:
      The inverse transform.
      Throws:
      NoninvertibleTransformException - if the transform can't be inversed.

    • isIdentity

      public boolean isIdentity()
      Tests whether this transform does not move any points.
      Specified by:
      isIdentity in interface MathTransform
      Overrides:
      isIdentity in class AbstractMathTransform
      Returns:
      true if this MathTransform is an identity transform; false otherwise.

    • isIdentity

      public boolean isIdentity(double tolerance)
      Tests whether this transform does not move any points by using the provided tolerance. This method work in the same way than XMatrix.isIdentity(double).
      Specified by:
      isIdentity in interface LinearTransform
      Parameters:
      tolerance - The tolerance factor.
      Returns:
      true if this transform is the identity one
      Since:
      2.3.1

    • derivative

      public Matrix derivative(Position point) throws 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 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.

    • derivative

      public double derivative(double value)
      Gets the derivative of this function at a value.
      Specified by:
      derivative in interface MathTransform1D
      Parameters:
      value - The value where to evaluate the derivative.
      Returns:
      The derivative at the specified point.

    • transform

      public double transform(double value)
      Transforms the specified value.
      Specified by:
      transform in interface MathTransform1D
      Parameters:
      value - The value to transform.
      Returns:
      the transformed value.

    • 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 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, double[] dstPts, int dstOff, int numPts)
      Transforms a list of coordinate point ordinal values.
      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.

    • 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(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.