Object
- FormattableObject
- - AbstractMathTransform
  - - DatumShiftTransform
    - - InterpolatedMolodenskyTransform

All Implemented Interfaces:

Serializable, Parameterized, LenientComparable, MathTransform
```
public class InterpolatedMolodenskyTransform
extends DatumShiftTransform
```
Transforms between two geographic CRS by performing geocentric translations interpolated from a grid file, but using Molodensky approximation. This transformation is conceptually defined as a translation in geocentric coordinates as performed by InterpolatedGeocentricTransform, but uses the Molodensy (non-abridged) approximation for performance reasons. Errors are less than 3 centimetres for the "France geocentric interpolation" (ESPG:9655). By comparison, the finest accuracy reported in the grid file for France is 5 centimetres.
Algorithm
This class transforms two- or three- dimensional coordinates from a geographic CRS to another geographic CRS. The changes between source and target coordinates are small (usually less than 400 metres), but vary for every position. Those changes are provided in a datum shift grid, usually loaded from one or two files.
Many datum shift grids like NADCON and NTv2 apply the interpolated translations directly on geographic coordinates. This relatively simple case is handled by InterpolatedTransform. But in the InterpolatedMolodenskyTransform case, the interpolated translations are rather the (tX, tY, tZ) parameters of a Molodensky transformation.

Since:

0.7

See Also:

InterpolatedGeocentricTransform, Serialized Form

Defined in the sis-referencing module

Field Summary

Fields
Modifier and Type	Field	Description
`protected double`	`eccentricitySquared`	The square of eccentricity of the source ellipsoid.
`protected double`	`semiMajor`	Semi-major axis length (`a`) of the source ellipsoid.
`protected double`	`tX`	Shift along the geocentric X axis (toward prime meridian) in units of the semi-major axis of the source ellipsoid.
`protected double`	`tY`	Shift along the geocentric Y axis (toward 90°E) in units of the semi-major axis of the source ellipsoid.
`protected double`	`tZ`	Shift along the geocentric Z axis (toward north pole) in units of the semi-major axis of the source ellipsoid.

Constructor Summary

Constructors
Modifier	Constructor	Description
`protected`	`InterpolatedMolodenskyTransform(Ellipsoid source, boolean isSource3D, Ellipsoid target, boolean isTarget3D, DatumShiftGrid<Angle,Length> grid)`	Creates a transform from the specified parameters.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected int`	`computeHashCode()`	Computes a hash value for this transform.
`static MathTransform`	`createGeodeticTransformation(MathTransformFactory factory, Ellipsoid source, boolean isSource3D, Ellipsoid target, boolean isTarget3D, DatumShiftGrid<Angle,Length> grid)`	Creates a transformation between two geographic CRS.
`boolean`	`equals(Object object, ComparisonMode mode)`	Compares the specified object with this math transform for equality.
`ParameterDescriptorGroup`	`getParameterDescriptors()`	Returns a description of the internal parameters of this `InterpolatedMolodenskyTransform` transform.
`ParameterValueGroup`	`getParameterValues()`	Returns a copy of internal parameter values of this transform.
`int`	`getSourceDimensions()`	Gets the dimension of input points.
`int`	`getTargetDimensions()`	Gets the dimension of output points.
`MathTransform`	`inverse()`	Returns the inverse of this interpolated Molodensky transform.
`Matrix`	`transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate)`	Transforms the (λ,φ) or (λ,φ,`h`) coordinates between two geographic CRS, and optionally returns the derivative at that location.
`void`	`transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts)`	Transforms the (λ,φ) or (λ,φ,`h`) coordinates between two geographic CRS.

Methods inherited from class DatumShiftTransform
getContextualParameters

Methods inherited from class AbstractMathTransform
derivative, equals, formatTo, hashCode, isIdentity, transform, transform, transform, transform, tryConcatenate

Methods inherited from class FormattableObject
print, toString, toString, toWKT

Methods inherited from class Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface MathTransform
toWKT

- Field Detail
  - tX
```
protected final double tX
```
    Shift along the geocentric X axis (toward prime meridian) in units of the semi-major axis of the source ellipsoid.
    
    See Also:
    
    BursaWolfParameters.tX
  - tY
```
protected final double tY
```
    Shift along the geocentric Y axis (toward 90°E) in units of the semi-major axis of the source ellipsoid.
    
    See Also:
    
    BursaWolfParameters.tY
  - tZ
```
protected final double tZ
```
    Shift along the geocentric Z axis (toward north pole) in units of the semi-major axis of the source ellipsoid.
    
    See Also:
    
    BursaWolfParameters.tZ
  - semiMajor
```
protected final double semiMajor
```
    Semi-major axis length (a) of the source ellipsoid.
  - eccentricitySquared
```
protected final double eccentricitySquared
```
    The square of eccentricity of the source ellipsoid. This can be computed by ℯ² = (a²-b²)/a² where a is the semi-major axis length and b is the semi-minor axis length.
    
    See Also:
    
    DefaultEllipsoid.getEccentricitySquared()
- Constructor Detail
  - InterpolatedMolodenskyTransform
```
protected InterpolatedMolodenskyTransform(Ellipsoid source,
                                          boolean isSource3D,
                                          Ellipsoid target,
                                          boolean isTarget3D,
                                          DatumShiftGrid<Angle,Length> grid)
```
    Creates a transform from the specified parameters. This InterpolatedMolodenskyTransform class expects coordinate values in the following order and units:
    
    longitudes in radians relative to the prime meridian (usually Greenwich),
    
    latitudes in radians,
    
    optionally heights above the ellipsoid, in same units than the source ellipsoid axes.
    
    For converting geographic coordinates in degrees, InterpolatedMolodenskyTransform instances need to be concatenated with the following affine transforms:
    
    Normalization before InterpolatedMolodenskyTransform:
    
    Conversion of (λ,φ) from degrees to radians.
    
    Denormalization after InterpolatedMolodenskyTransform:
    
    Conversion of (λ,φ) from radians to degrees.
    
    After InterpolatedMolodenskyTransform construction, the full conversion chain including the above affine transforms can be created by DatumShiftTransform.getContextualParameters().completeTransform(factory, this)}.
    Parameters:
    
    source - the source ellipsoid.
    
    isSource3D - true if the source coordinates have a height.
    
    target - the target ellipsoid.
    
    isTarget3D - true if the target coordinates have a height.
    
    grid - the grid of datum shifts from source to target datum. The DatumShiftGrid.interpolateInCell(…) method shall compute (ΔX, ΔY, ΔZ) translations from source to target in the unit of source ellipsoid axes.
    
    See Also:
    
    createGeodeticTransformation(MathTransformFactory, Ellipsoid, boolean, Ellipsoid, boolean, DatumShiftGrid)
- Method Detail
  - createGeodeticTransformation
```
public static MathTransform createGeodeticTransformation(MathTransformFactory factory,
                                                         Ellipsoid source,
                                                         boolean isSource3D,
                                                         Ellipsoid target,
                                                         boolean isTarget3D,
                                                         DatumShiftGrid<Angle,Length> grid)
                                                  throws FactoryException
```
    Creates a transformation between two geographic CRS. This factory method combines the InterpolatedMolodenskyTransform instance with the steps needed for converting values between degrees to radians. The transform works with input and output coordinates in the following units:
    
    longitudes in degrees relative to the prime meridian (usually Greenwich),
    
    latitudes in degrees,
    
    optionally heights above the ellipsoid, in same units than the source ellipsoids axes.
    
    Note however that the given grid instance shall expect geographic coordinates (λ,φ) in radians.
    Parameters:
    
    factory - the factory to use for creating the transform.
    
    source - the source ellipsoid.
    
    isSource3D - true if the source coordinates have a height.
    
    target - the target ellipsoid.
    
    isTarget3D - true if the target coordinates have a height.
    
    grid - the grid of datum shifts from source to target datum. The DatumShiftGrid.interpolateInCell(…) method shall compute (ΔX, ΔY, ΔZ) translations from source to target in the unit of source ellipsoid axes.
    
    Returns:
    
    the transformation between geographic coordinates in degrees.
    
    Throws:
    
    FactoryException - if an error occurred while creating a transform.
  - transform
```
public Matrix transform(double[] srcPts,
                        int srcOff,
                        double[] dstPts,
                        int dstOff,
                        boolean derivate)
                 throws TransformException
```
    Transforms the (λ,φ) or (λ,φ,h) coordinates between two geographic CRS, and optionally returns the derivative at that location.
    
    Specified by:
    
    transform in class AbstractMathTransform
    
    Parameters:
    
    srcPts - the array containing the source coordinate (can not be null).
    
    srcOff - the offset to the point to be transformed in the source array.
    
    dstPts - the array into which the transformed coordinate is returned. May be the same than srcPts. May be null if only the derivative matrix is desired.
    
    dstOff - the offset to the location of the transformed point that is stored in the destination array.
    
    derivate - true for computing the derivative, or false if not needed.
    
    Returns:
    
    the matrix of the transform derivative at the given source position, or null if the derivate argument is false.
    
    Throws:
    
    TransformException - if the point can not be transformed or if a problem occurred while calculating the derivative.
    
    See Also:
    
    AbstractMathTransform.derivative(DirectPosition), AbstractMathTransform.transform(DirectPosition, DirectPosition), MathTransforms.derivativeAndTransform(MathTransform, double[], int, double[], int)
  - transform
```
public void transform(double[] srcPts,
                      int srcOff,
                      double[] dstPts,
                      int dstOff,
                      int numPts)
               throws TransformException
```
    Transforms the (λ,φ) or (λ,φ,h) coordinates between two geographic CRS. This method performs the same work than the above transform(…) method, but on an arbitrary amount of coordinates and without computing derivative.
    
    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 not be transformed.
  - inverse
```
public MathTransform inverse()
```
    Returns the inverse of this interpolated Molodensky transform. The source ellipsoid of the returned transform will be the target ellipsoid of this transform, and conversely.
    
    Specified by:
    
    inverse in interface MathTransform
    
    Overrides:
    
    inverse in class AbstractMathTransform
    
    Returns:
    
    a transform from the target ellipsoid to the source ellipsoid of this transform.
  - getParameterDescriptors
```
@Debug
public ParameterDescriptorGroup getParameterDescriptors()
```
    Returns a description of the internal parameters of this InterpolatedMolodenskyTransform transform. The returned group contains parameters for the source ellipsoid semi-axis lengths and the differences between source and target ellipsoid parameters.
    Note: this method is mostly for debugging purposes since the isolation of non-linear parameters in this class is highly implementation dependent. Most GIS applications will instead be interested in the contextual parameters.
    
    Specified by:
    
    getParameterDescriptors in interface Parameterized
    
    Overrides:
    
    getParameterDescriptors in class AbstractMathTransform
    
    Returns:
    
    a description of the internal parameters.
    
    See Also:
    
    DefaultOperationMethod.getParameters()
  - getParameterValues
```
@Debug
public ParameterValueGroup getParameterValues()
```
    Returns a copy of internal parameter values of this transform. The returned group contains parameters for the source ellipsoid semi-axis lengths and the differences between source and target ellipsoid parameters.
    Note: this method is mostly for debugging purposes since the isolation of non-linear parameters in this class is highly implementation dependent. Most GIS applications will instead be interested in the contextual parameters.
    
    Specified by:
    
    getParameterValues in interface Parameterized
    
    Overrides:
    
    getParameterValues in class DatumShiftTransform
    
    Returns:
    
    a copy of the internal parameter values for this transform.
    
    See Also:
    
    AbstractMathTransform.getContextualParameters(), SingleOperation.getParameterValues()
  - 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 input dimension, which is 2 or 3.
    
    See Also:
    
    DefaultOperationMethod.getSourceDimensions()
  - 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 output dimension, which is 2 or 3.
    
    See Also:
    
    DefaultOperationMethod.getTargetDimensions()
  - 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 DatumShiftTransform
    
    Returns:
    
    the hash code value. This value may change between different execution of the Apache SIS library.
  - equals
```
public boolean equals(Object object,
                      ComparisonMode mode)
```
    Compares the specified object with this math transform for equality.
    
    Specified by:
    
    equals in interface LenientComparable
    
    Overrides:
    
    equals in class DatumShiftTransform
    
    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 considered equals to this math transform.

Class InterpolatedMolodenskyTransform

Field Summary

Constructor Summary

Method Summary

Methods inherited from class DatumShiftTransform

Methods inherited from class AbstractMathTransform

Methods inherited from class FormattableObject

Methods inherited from class Object

Methods inherited from interface MathTransform

Field Detail

tX

tY

tZ

semiMajor

eccentricitySquared

Constructor Detail

InterpolatedMolodenskyTransform

Method Detail

createGeodeticTransformation

transform

transform

inverse

getParameterDescriptors

getParameterValues

getSourceDimensions

getTargetDimensions

computeHashCode

equals