Module org.apache.sis.referencing

Package org.apache.sis.referencing.operation

Class DefaultTransformation

Object

FormattableObject

AbstractIdentifiedObject

AbstractCoordinateOperation

DefaultTransformation

All Implemented Interfaces:

Serializable, Formattable, Parameterized, Deprecable, Lenient­Comparable, Identified­Object, Coordinate­Operation, Single­Operation, Transformation

public class DefaultTransformation
extends AbstractCoordinateOperation
implements Transformation

A parameterized mathematical operation that transforms coordinates to another CRS with a change of datum. The parameters of a coordinate transformation are empirically derived from data containing the coordinates of a series of points in both coordinate reference systems. This computational process is usually "over-determined", allowing derivation of error (or accuracy) estimates for the transformation. Also, the stochastic nature of the parameters may result in multiple (different) versions of the same coordinate transformation.

This coordinate operation contains an operation method, usually with associated parameter values. In the SIS default implementation, the parameter values are inferred from the math transform. Subclasses may have to override the Single­Operation.get­Parameter­Values() method if they need to provide a different set of parameters.

Immutability and thread safety

This class is immutable and thus thread-safe if the property values (not necessarily the map itself) given to the constructor are also immutable. This means that unless otherwise noted in the javadoc, Transformation instances created using only SIS factories and static constants can be shared by many objects and passed between threads without synchronization.

Since:

0.6

See Also:

• Default­Conversion
• Serialized Form

Field Summary

Fields inherited from class AbstractIdentifiedObject

DEPRECATED_KEY, LOCALE_KEY

Fields inherited from interface CoordinateOperation

COORDINATE_OPERATION_ACCURACY_KEY, DOMAIN_OF_VALIDITY_KEY, OPERATION_VERSION_KEY, SCOPE_KEY

Fields inherited from interface IdentifiedObject

ALIAS_KEY, IDENTIFIERS_KEY, NAME_KEY, REMARKS_KEY

Constructor Summary

Constructors

Modifier	Constructor	Description
	Default­Transformation(Map<String,?> properties, Coordinate­Reference­System source­CRS, Coordinate­Reference­System target­CRS, Coordinate­Reference­System interpolation­CRS, Operation­Method method, Math­Transform transform)	Creates a coordinate transformation from the given properties.
protected	Default­Transformation(Transformation operation)	Creates a new coordinate operation with the same values than the specified one.

Method Summary

Modifier and Type	Method	Description
static Default­Transformation	cast­Or­Copy(Transformation object)	Returns a SIS coordinate operation implementation with the values of the given arbitrary implementation.
boolean	equals(Object object, Comparison­Mode mode)	Compares this coordinate operation with the specified object for equality.
Class<? extends Transformation>	get­Interface()	Returns the GeoAPI interface implemented by this class.
Operation­Method	get­Method()	Returns a description of the operation method, including a list of expected parameter names.
Parameter­Descriptor­Group	get­Parameter­Descriptors()	Returns a description of the parameters.
Parameter­Value­Group	get­Parameter­Values()	Returns the parameter values.

Methods inherited from class AbstractCoordinateOperation

cast­Or­Copy, compute­Hash­Code, format­To, get­Coordinate­Operation­Accuracy, get­Domain­Of­Validity, get­Interpolation­CRS, get­Linear­Accuracy, get­Math­Transform, get­Operation­Version, get­Scope, get­Source­CRS, get­Target­CRS, get­Wrap­Around­Changes, is­Defining­Conversion

Methods inherited from class AbstractIdentifiedObject

cast­Or­Copy, equals, format­To, get­Alias, get­Description, get­Domains, get­Identifiers, get­Name, get­Remarks, hash­Code, is­Deprecated, is­Heuristic­Match­For­Name

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 CoordinateOperation

get­Coordinate­Operation­Accuracy, get­Domain­Of­Validity, get­Math­Transform, get­Scope

Methods inherited from interface IdentifiedObject

get­Alias, get­Identifiers, get­Name, get­Remarks, to­WKT

Methods inherited from interface SingleOperation

get­Method, get­Parameter­Values

Methods inherited from interface Transformation

get­Operation­Version, get­Source­CRS, get­Target­CRS

Constructor Details

DefaultTransformation

public DefaultTransformation(Map<String,?> properties,
 CoordinateReferenceSystem sourceCRS,
 CoordinateReferenceSystem targetCRS,
 CoordinateReferenceSystem interpolationCRS,
 OperationMethod method,
 MathTransform transform)

Creates a coordinate transformation from the given properties. The properties given in argument follow the same rules than for the super-class constructor. The following table is a reminder of main (not all) properties:

Recognized properties (non exhaustive list)

Property name	Value type	Returned by
"name"	Identifier or String	AbstractIdentifiedObject.getName()
"identifiers"	Identifier (optionally as array)	AbstractIdentifiedObject.getIdentifiers()
"coordinateOperationAccuracy"	PositionalAccuracy (optionally as array)	AbstractCoordinateOperation.getCoordinateOperationAccuracy()
"domainOfValidity"	Extent	AbstractCoordinateOperation.getDomainOfValidity()

Parameters:

properties - the properties to be given to the identified object.

source­CRS - the source CRS.

target­CRS - the target CRS.

interpolation­CRS - the CRS of additional coordinates needed for the operation, or null if none.

method - the coordinate operation method (mandatory in all cases).

transform - transform from positions in the source CRS to positions in the target CRS.

DefaultTransformation

protected DefaultTransformation(Transformation operation)

Creates a new coordinate operation with the same values than the specified one. This copy constructor provides a way to convert an arbitrary implementation into a SIS one or a user-defined one (as a subclass), usually in order to leverage some implementation-specific API.

This constructor performs a shallow copy, i.e. the properties are not cloned.

Parameters:

operation - the coordinate operation to copy.

See Also:

• cast­Or­Copy(Transformation)

Method Details

castOrCopy

public static DefaultTransformation castOrCopy(Transformation object)

Returns a SIS coordinate operation implementation with the values of the given arbitrary implementation. If the given object is already an instance of Default­Transformation, then it is returned unchanged. Otherwise a new Default­Transformation instance is created using the copy constructor and returned. Note that this is a shallow copy operation, because the other properties contained in the given object are not recursively copied.

Parameters:

object - the object to get as a SIS implementation, or null if none.

Returns:

a SIS implementation containing the values of the given object (may be the given object itself), or null if the argument was null.

getInterface

public Class<? extends Transformation> getInterface()

Returns the GeoAPI interface implemented by this class. The SIS implementation returns Transformation.class.

Note for implementers

Subclasses usually do not need to override this method since GeoAPI does not define Transformation sub-interface. Overriding possibility is left mostly for implementers who wish to extend GeoAPI with their own set of interfaces.

Overrides:

get­Interface in class Abstract­Coordinate­Operation

Returns:

Transformation.class or a user-defined sub-interface.

getMethod

public OperationMethod getMethod()

Returns a description of the operation method, including a list of expected parameter names. The returned object does not contains any parameter value.

Specified by:

get­Method in interface Single­Operation

Returns:

a description of the operation method.

getParameterDescriptors

public ParameterDescriptorGroup getParameterDescriptors()

Returns a description of the parameters. The default implementation performs the following choice:

• If parameter values were specified explicitly at construction time, then the descriptor of those parameters is returned.
• Otherwise if this method can infer the parameter descriptor from the math transform, then that descriptor is returned.
• Otherwise fallback on the method parameters.

Note: the two parameter descriptions (from the Math­Transform or from the Operation­Method) should be very similar. If they differ, it should be only in minor details like remarks, default values or units of measurement.

Specified by:

get­Parameter­Descriptors in interface Parameterized

Returns:

a description of the parameters.

See Also:

• Default­Operation­Method.get­Parameters()
• Abstract­Math­Transform.get­Parameter­Descriptors()

getParameterValues

public ParameterValueGroup getParameterValues()

Returns the parameter values. The default implementation performs the following choice:

• If parameter values were specified explicitly at construction time, then they are returned as an unmodifiable parameter group.
• Otherwise if this method can infer the parameter values from the math transform, then those parameters are returned.
• Otherwise throw Unsupported­Implementation­Exception.

Specified by:

get­Parameter­Values in interface Parameterized

Specified by:

get­Parameter­Values in interface Single­Operation

Returns:

the parameter values.

Throws:

Unsupported­Operation­Exception - if the parameter values cannot be determined for the current math transform implementation.

See Also:

• Abstract­Math­Transform.get­Parameter­Values()

equals

public boolean equals(Object object,
 ComparisonMode mode)

Compares this coordinate operation with the specified object for equality. If the mode argument is Comparison­Mode.STRICT or BY_CONTRACT, then all available properties are compared including the domain of validity and the scope.

Specified by:

equals in interface Lenient­Comparable

Overrides:

equals in class Abstract­Coordinate­Operation

Parameters:

object - the object to compare to this.

mode - STRICT for performing a strict comparison, or IGNORE_METADATA for ignoring properties that do not make a difference in the numerical results of coordinate operations.

Returns:

true if both objects are equal for the given comparison mode.

See Also:

• Abstract­Identified­Object.compute­Hash­Code()
• Utilities.deep­Equals(Object, Object, Comparison­Mode)