org.geotools.referencing.operation
Class AbstractCoordinateOperation

java.lang.Object
  org.geotools.referencing.wkt.Formattable
      org.geotools.referencing.AbstractIdentifiedObject
          org.geotools.referencing.operation.AbstractCoordinateOperation

All Implemented Interfaces:

org.opengis.referencing.operation.CoordinateOperation, org.opengis.referencing.IdentifiedObject, java.io.Serializable

Direct Known Subclasses:

DefaultConcatenatedOperation, DefaultSingleOperation

public class AbstractCoordinateOperation

extends AbstractIdentifiedObject

implements org.opengis.referencing.operation.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 prefix instead. An exception to this rule may occurs when it is not possible to identify the exact type.

Since:

2.1

Version:

$Id: AbstractCoordinateOperation.java 17890 2006-02-06 08:46:14Z desruisseaux $

Author:

Martin Desruisseaux

See Also:

Serialized Form

Field Summary

static org.opengis.metadata.quality.PositionalAccuracy[]	EMPTY_ACCURACY_ARRAY An empty array of positional accuracy.
protected org.opengis.referencing.crs.CoordinateReferenceSystem	sourceCRS The source CRS, or if not available.
protected org.opengis.referencing.crs.CoordinateReferenceSystem	targetCRS The target CRS, or if not available.
protected org.opengis.referencing.operation.MathTransform	transform Transform from positions in the source coordinate reference system to positions in the target coordinate reference system.
protected org.opengis.metadata.extent.Extent	validArea Area in which this operation is valid, or if not available.

Fields inherited from class org.geotools.referencing.AbstractIdentifiedObject

EMPTY_ALIAS_ARRAY, EMPTY_IDENTIFIER_ARRAY, IDENTIFIER_COMPARATOR, NAME_COMPARATOR, REMARKS_COMPARATOR

Fields inherited from interface org.opengis.referencing.operation.CoordinateOperation

OPERATION_VERSION_KEY, POSITIONAL_ACCURACY_KEY, SCOPE_KEY, VALID_AREA_KEY

Fields inherited from interface org.opengis.referencing.IdentifiedObject

ALIAS_KEY, IDENTIFIERS_KEY, NAME_KEY, REMARKS_KEY

Constructor Summary

AbstractCoordinateOperation(java.util.Map properties, org.opengis.referencing.crs.CoordinateReferenceSystem sourceCRS, org.opengis.referencing.crs.CoordinateReferenceSystem targetCRS, org.opengis.referencing.operation.MathTransform transform)
Constructs a coordinate operation from a set of properties.

Method Summary

boolean	equals(AbstractIdentifiedObject object, boolean compareMetadata) Compares this coordinate operation with the specified object for equality.
protected java.lang.String	formatWKT(Formatter formatter) Format the inner part of a Well Known Text (WKT) element.
double	getAccuracy() Convenience method returning the accuracy in meters.
static double	getAccuracy(org.opengis.referencing.operation.CoordinateOperation operation) Convenience method returning the accuracy in meters for the specified operation.
org.opengis.referencing.operation.MathTransform	getMathTransform() Gets the math transform.
java.lang.String	getOperationVersion() Version of the coordinate transformation (i.e., instantiation due to the stochastic nature of the parameters).
java.util.Collection	getPositionalAccuracy() Estimate(s) of the impact of this operation on point accuracy.
org.opengis.util.InternationalString	getScope() Description of domain of usage, or limitations of usage, for which this operation is valid.
org.opengis.referencing.crs.CoordinateReferenceSystem	getSourceCRS() Returns the source CRS.
org.opengis.referencing.crs.CoordinateReferenceSystem	getTargetCRS() Returns the target CRS.
static java.lang.Class	getType(org.opengis.referencing.operation.CoordinateOperation object) Returns the most specific GeoAPI interface implemented by the specified operation.
org.opengis.metadata.extent.Extent	getValidArea() Area in which this operation is valid.
int	hashCode() Returns a hash code value for this coordinate operation.

Methods inherited from class org.geotools.referencing.AbstractIdentifiedObject

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

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.IdentifiedObject

getAlias, getIdentifiers, getName, getRemarks, toWKT

Field Detail

EMPTY_ACCURACY_ARRAY

public static final org.opengis.metadata.quality.PositionalAccuracy[] EMPTY_ACCURACY_ARRAY

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

 getPositionalAccuracy().toArray(EMPTY_ACCURACY_ARRAY);
 

sourceCRS

protected final org.opengis.referencing.crs.CoordinateReferenceSystem sourceCRS

The source CRS, or if not available.

targetCRS

protected final org.opengis.referencing.crs.CoordinateReferenceSystem targetCRS

The target CRS, or if not available.

validArea

protected final org.opengis.metadata.extent.Extent validArea

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

transform

protected final org.opengis.referencing.operation.MathTransform transform

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

Constructor Detail

AbstractCoordinateOperation

public AbstractCoordinateOperation(java.util.Map properties,
                                   org.opengis.referencing.crs.CoordinateReferenceSystem sourceCRS,
                                   org.opengis.referencing.crs.CoordinateReferenceSystem targetCRS,
                                   org.opengis.referencing.operation.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()
"positionalAccuracy"	PositionalAccuracy[]	getPositionalAccuracy()
"validArea"	Extent	getValidArea()
"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 org.opengis.referencing.crs.CoordinateReferenceSystem getSourceCRS()

Returns the source CRS.

Specified by:

getSourceCRS in interface org.opengis.referencing.operation.CoordinateOperation

getTargetCRS

public org.opengis.referencing.crs.CoordinateReferenceSystem getTargetCRS()

Returns the target CRS.

Specified by:

getTargetCRS in interface org.opengis.referencing.operation.CoordinateOperation

getOperationVersion

public java.lang.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 org.opengis.referencing.operation.CoordinateOperation

Returns:

The coordinate operation version, or in none.

getPositionalAccuracy

public java.util.Collection getPositionalAccuracy()

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:

getPositionalAccuracy in interface org.opengis.referencing.operation.CoordinateOperation

Returns:

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

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.

Since:

2.2

getAccuracy

public static double getAccuracy(org.opengis.referencing.operation.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

getValidArea

public org.opengis.metadata.extent.Extent getValidArea()

Area in which this operation is valid.

Specified by:

getValidArea in interface org.opengis.referencing.operation.CoordinateOperation

Returns:

Coordinate operation valid area, or if not available.

getScope

public org.opengis.util.InternationalString getScope()

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

Specified by:

getScope in interface org.opengis.referencing.operation.CoordinateOperation

getMathTransform

public org.opengis.referencing.operation.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 org.opengis.referencing.operation.CoordinateOperation

getType

public static java.lang.Class getType(org.opengis.referencing.operation.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 is , then all available properties are compared including valid area and scope.

Overrides:

equals in class AbstractIdentifiedObject

Parameters:

object - The object to compare to .

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

Returns:

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 java.lang.String formatWKT(Formatter formatter)

Format the inner part of a Well Known Text (WKT) element.

Overrides:

formatWKT in class Formattable

Parameters:

formatter - The formatter to use.

Returns:

The WKT element name.

See Also:

Formattable.toWKT(), Formattable.toString()