org.geotools.referencing.operation

Class AbstractCoordinateOperation

Object

Formattable

AbstractIdentifiedObject

AbstractCoordinateOperation

All Implemented Interfaces:

Serializable, IdentifiedObject, CoordinateOperation

Direct Known Subclasses:

DefaultConcatenatedOperation, DefaultSingleOperation

public class AbstractCoordinateOperation
extends AbstractIdentifiedObject
implements CoordinateOperation

Establishes an association between a source and a target coordinate reference system, and provides a transform for transforming coordinates in the source CRS to coordinates in the target CRS. Many but not all coordinate operations (from coordinate reference system A to coordinate reference system B) also uniquely define the inverse operation (from coordinate reference system B to coordinate reference system A). In some cases, the operation method algorithm for the inverse operation is the same as for the forward algorithm, but the signs of some operation parameter values must be reversed. In other cases, different algorithms are required for the forward and inverse operations, but the same operation parameter values are used. If (some) entirely different parameter values are needed, a different coordinate operation shall be defined.

This class is conceptually abstract, even if it is technically possible to instantiate it. Typical applications should create instances of the most specific subclass with Default prefix instead. An exception to this rule may occurs when it is not possible to identify the exact type.

Since:

2.1

Author:

Martin Desruisseaux (IRD)

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected Extent	domainOfValidity Area in which this operation is valid, or null if not available.
static PositionalAccuracy[]	EMPTY_ACCURACY_ARRAY An empty array of positional accuracy.
protected CoordinateReferenceSystem	sourceCRS The source CRS, or null if not available.
protected CoordinateReferenceSystem	targetCRS The target CRS, or null if not available.
protected MathTransform	transform Transform from positions in the source coordinate reference system to positions in the target coordinate reference system.

Fields inherited from class AbstractIdentifiedObject

EMPTY_ALIAS_ARRAY, EMPTY_IDENTIFIER_ARRAY, IDENTIFIER_COMPARATOR, NAME_COMPARATOR, REMARKS_COMPARATOR

Fields inherited from class Formattable

SINGLE_LINE

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

Constructor and Description
AbstractCoordinateOperation(Map<String,?> properties, CoordinateReferenceSystem sourceCRS, CoordinateReferenceSystem targetCRS, MathTransform transform) Constructs a coordinate operation from a set of properties.

Method Summary

Modifier and Type	Method and Description
boolean	equals(AbstractIdentifiedObject object, boolean compareMetadata) Compares this coordinate operation with the specified object for equality.
protected String	formatWKT(Formatter formatter) Format this operation as a pseudo-WKT format.
double	getAccuracy() Convenience method returning the accuracy in meters.
static double	getAccuracy(CoordinateOperation operation) Convenience method returning the accuracy in meters for the specified operation.
Collection<PositionalAccuracy>	getCoordinateOperationAccuracy() Estimate(s) of the impact of this operation on point accuracy.
Extent	getDomainOfValidity() Area or region or timeframe in which this coordinate operation is valid.
MathTransform	getMathTransform() Gets the math transform.
String	getOperationVersion() Version of the coordinate transformation (i.e., instantiation due to the stochastic nature of the parameters).
InternationalString	getScope() Description of domain of usage, or limitations of usage, for which this operation is valid.
CoordinateReferenceSystem	getSourceCRS() Returns the source CRS.
CoordinateReferenceSystem	getTargetCRS() Returns the target CRS.
static Class<? extends CoordinateOperation>	getType(CoordinateOperation object) Returns the most specific GeoAPI interface implemented by the specified operation.
int	hashCode() Returns a hash code value for this coordinate operation.

Methods inherited from class AbstractIdentifiedObject

asSet, ensureAngularUnit, ensureLinearUnit, ensureNonNull, ensureNonNull, ensureTimeUnit, equals, equals, equals, equals, getAlias, getIdentifier, getIdentifier, getIdentifiers, getName, getName, getName, getProperties, getProperties, getRemarks, nameMatches, nameMatches, nameMatches

Methods inherited from class Formattable

cleanupThreadLocals, toString, toWKT, toWKT, toWKT, toWKT

Methods inherited from class Object

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

Methods inherited from interface IdentifiedObject

getAlias, getIdentifiers, getName, getRemarks, toWKT

Field Detail

EMPTY_ACCURACY_ARRAY

public static final PositionalAccuracy[] EMPTY_ACCURACY_ARRAY

An empty array of positional accuracy. This is usefull for fetching accuracies as an array, using the following idiom:

 getCoordinateOperationAccuracy().toArray(EMPTY_ACCURACY_ARRAY);
 

sourceCRS

protected final CoordinateReferenceSystem sourceCRS

The source CRS, or null if not available.

targetCRS

protected final CoordinateReferenceSystem targetCRS

The target CRS, or null if not available.

domainOfValidity

protected final Extent domainOfValidity

Area in which this operation is valid, or null if not available.

transform

protected final MathTransform transform

Transform from positions in the source coordinate reference system to positions in the target coordinate reference system.

Constructor Detail

AbstractCoordinateOperation

public AbstractCoordinateOperation(Map<String,?> properties,
                                   CoordinateReferenceSystem sourceCRS,
                                   CoordinateReferenceSystem targetCRS,
                                   MathTransform transform)

Constructs a coordinate operation from a set of properties. The properties given in argument follow the same rules than for the super-class constructor. Additionally, the following properties are understood by this construtor:

Property name	Value type	Value given to
"operationVersion"	String	getOperationVersion()
"coordinateOperationAccuracy"	PositionalAccuracy[]	getCoordinateOperationAccuracy()
"domainOfValidity"	Extent	getDomainOfValidity()
"scope"	String or InternationalString	getScope()

Parameters:

properties - Set of properties. Should contains at least "name".

sourceCRS - The source CRS.

targetCRS - The target CRS.

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

Method Detail

getSourceCRS

public CoordinateReferenceSystem getSourceCRS()

Returns the source CRS.

Specified by:

getSourceCRS in interface CoordinateOperation

Returns:

The source CRS, or null if not available.

See Also:

Conversion.getSourceCRS(), Transformation.getSourceCRS()

getTargetCRS

public CoordinateReferenceSystem getTargetCRS()

Returns the target CRS.

Specified by:

getTargetCRS in interface CoordinateOperation

Returns:

The target CRS, or null if not available.

See Also:

Conversion.getTargetCRS(), Transformation.getTargetCRS()

getOperationVersion

public String getOperationVersion()

Version of the coordinate transformation (i.e., instantiation due to the stochastic nature of the parameters). Mandatory when describing a transformation, and should not be supplied for a conversion.

Specified by:

getOperationVersion in interface CoordinateOperation

Returns:

The coordinate operation version, or null in none.

getCoordinateOperationAccuracy

public Collection<PositionalAccuracy> getCoordinateOperationAccuracy()

Estimate(s) of the impact of this operation on point accuracy. Gives position error estimates for target coordinates of this coordinate operation, assuming no errors in source coordinates.

Specified by:

getCoordinateOperationAccuracy in interface CoordinateOperation

Returns:

The position error estimates, or an empty collection if not available.

Since:

2.4

See Also:

getAccuracy()

getAccuracy

public double getAccuracy()

Convenience method returning the accuracy in meters. The default implementation delegates to getAccuracy(this). Subclasses should override this method if they can provide a more accurate algorithm.

Returns:

The accuracy in meters, or NaN if unknown.

Since:

2.2

getAccuracy

public static double getAccuracy(CoordinateOperation operation)

Convenience method returning the accuracy in meters for the specified operation. This method try each of the following procedures and returns the first successful one:

• If a quantitative positional accuracy is found with a linear unit, then this accuracy estimate is converted to meters and returned.
• Otherwise, if the operation is a conversion, then returns 0 since a conversion is by definition accurates up to rounding errors.
• Otherwise, if the operation is a transformation, then checks if the datum shift were applied with the help of Bursa-Wolf parameters. This procedure looks for Geotools-specific DATUM_SHIFT_APPLIED and DATUM_SHIFT_OMITTED metadata. If a datum shift has been applied, returns 25 meters. If a datum shift should have been applied but has been omitted, returns 1000 meters. The 1000 meters value is higher than the highest value (999 meters) found in the EPSG database version 6.7. The 25 meters value is the next highest value found in the EPSG database for a significant number of transformations.
• Otherwise, if the operation is a concatenated one, returns the sum of the accuracy of all components.

Parameters:

operation - The operation to inspect for accuracy.

Returns:

The accuracy estimate (always in meters), or NaN if unknow.

Since:

2.2

getDomainOfValidity

public Extent getDomainOfValidity()

Area or region or timeframe in which this coordinate operation is valid. Returns null if not available.

Specified by:

getDomainOfValidity in interface CoordinateOperation

Returns:

The coordinate operation valid domain, or null if not available.

Since:

2.4

getScope

public InternationalString getScope()

Description of domain of usage, or limitations of usage, for which this operation is valid.

Specified by:

getScope in interface CoordinateOperation

Returns:

A description of domain of usage, or null if none.

getMathTransform

public MathTransform getMathTransform()

Gets the math transform. The math transform will transform positions in the source coordinate reference system into positions in the target coordinate reference system.

Specified by:

getMathTransform in interface CoordinateOperation

Returns:

The transform from source to target CRS, or null if not applicable.

getType

public static Class<? extends CoordinateOperation> getType(CoordinateOperation object)

Returns the most specific GeoAPI interface implemented by the specified operation.

Parameters:

object - A coordinate operation.

Returns:

The most specific GeoAPI interface (e.g. Transformation.class ).

equals

public boolean equals(AbstractIdentifiedObject object,
                      boolean compareMetadata)

Compares this coordinate operation with the specified object for equality. If compareMetadata is true, then all available properties are compared including domain of validity and scope.

Overrides:

equals in class AbstractIdentifiedObject

Parameters:

object - The object to compare to this.

compareMetadata - true for performing a strict comparaison, or false for comparing only properties relevant to transformations.

Returns:

true if both objects are equal.

hashCode

public int hashCode()

Returns a hash code value for this coordinate operation.

Overrides:

hashCode in class AbstractIdentifiedObject

Returns:

The hash code value. This value doesn't need to be the same in past or future versions of this class.

formatWKT

protected String formatWKT(Formatter formatter)

Format this operation as a pseudo-WKT format. No WKT format were defined for coordinate operation at the time this method was written. This method may change in any future version until a standard format is found.

Overrides:

formatWKT in class Formattable

Parameters:

formatter - The formatter to use.

Returns:

The WKT element name.

See Also:

Formattable.toWKT(), Formattable.toString()