Module org.opengis.geoapi

Package org.opengis.referencing.operation

Interface OperationMethod

All Superinterfaces:

IdentifiedObject

@UML(identifier="OperationMethod",
     specification=ISO_19111)
public interface OperationMethod
extends IdentifiedObject

Algorithm or procedure used to perform a coordinate operation. Most operation methods use a number of operation parameters, although some coordinate conversions use none. Each coordinate operation using the method assigns values to these parameters.

As this class comes close to the heart of any coordinate transformation software, it is recommended to make extensive use of identifiers, referencing well-known datasets wherever possible. The name may be ambiguous because there is yet no standard way of spelling or naming the various coordinate operation methods. Client software requesting a coordinate operation to be executed by a coordinate transformation implementation may therefore ask for an operation method this server doesn't recognise, although a perfectly valid method may be available. Some recommended EPSG identifiers are reproduced below (see ISO 19162 or the EPSG repository for a more complete list):

EPSG identifier for some operation method names

Name	Alias	Identifier
Albers Equal Area	Albers	9822
Hotine Oblique Mercator (variant A)	Rectified skew orthomorphic	9812
Hotine Oblique Mercator (variant B)	Rectified skew orthomorphic	9815
Lambert Azimuthal Equal Area	Lambert Equal Area	9820
Lambert Conic Conformal (1SP)	Lambert Conic Conformal	9801
Lambert Conic Conformal (2SP)	Lambert Conic Conformal	9802
Mercator (variant A)	Mercator	9804
Mercator (variant B)	Mercator	9805
Oblique stereographic	Double stereographic	9809
Transverse Mercator	Gauss-Boaga / Gauss-Krüger	9807

Example

An operation method named Mercator (variant A) (EPSG:9804) declares the following parameters. Note that implementations can optionally assign default values to those parameters.

• Latitude of natural origin in degrees.
• Longitude of natural origin in degrees.
• Scale factor at natural origin as a dimensionless number.
• False easting in metres.
• False northing in metres.

Since:

1.0

See Also:

• CoordinateOperation
• MathTransformFactory.getAvailableMethods(Class)
• CoordinateOperationFactory.getOperationMethod(String)
• CoordinateOperationAuthorityFactory.createOperationMethod(String)
• CoordinateOperationFactory.createOperationMethod(Map, ParameterDescriptorGroup)

Field Summary

Fields

Modifier and Type	Field	Description
static final String	FORMULA_KEY	Key for the "formula" property.

Fields inherited from interface org.opengis.referencing.IdentifiedObject

ALIAS_KEY, DOMAINS_KEY, IDENTIFIERS_KEY, NAME_KEY, REMARKS_KEY

Method Summary

Modifier and Type	Method	Description
Formula	getFormula()	Formula(s) or procedure used by this operation method.
ParameterDescriptorGroup	getParameters()	Returns the set of parameters.
default Integer	getSourceDimensions()	Deprecated. This attribute has been removed from ISO 19111:2019.
default Integer	getTargetDimensions()	Deprecated. This attribute has been removed from ISO 19111:2019.

Methods inherited from interface org.opengis.referencing.IdentifiedObject

getAlias, getDomains, getIdentifiers, getName, getRemarks, toWKT

Field Details

FORMULA_KEY

static final String FORMULA_KEY

Key for the "formula" property. This is used for setting the value to be returned by getFormula().

See Also:

• getFormula()
• Constant Field Values

Method Details

getFormula

@UML(identifier="formulaReference",
     obligation=MANDATORY,
     specification=ISO_19111)
Formula getFormula()

Formula(s) or procedure used by this operation method. This may be a reference to a publication. Note that the operation method may not be analytic, in which case this attribute references or contains the procedure, not an analytic formula.

Returns:

the formula used by this method.

getSourceDimensions

@Deprecated(since="3.1")
@UML(identifier="sourceDimensions",
     obligation=OPTIONAL,
     specification=ISO_19111,
     version=2007)
default Integer getSourceDimensions()

Deprecated.

This attribute has been removed from ISO 19111:2019.

Number of dimensions in the source CRS of this operation method. Note that some operation methods work with an arbitrary number of dimensions (e.g. Affine Transform) and may return null.

Returns:

the dimension of source CRS, or null if unknown.

See Also:

• MathTransform.getSourceDimensions()

getTargetDimensions

@Deprecated(since="3.1")
@UML(identifier="targetDimensions",
     obligation=OPTIONAL,
     specification=ISO_19111,
     version=2007)
default Integer getTargetDimensions()

Deprecated.

This attribute has been removed from ISO 19111:2019.

Number of dimensions in the target CRS of this operation method. Note that some operation methods work with an arbitrary number of dimensions (e.g. Affine Transform) and may return null.

Returns:

the dimension of target CRS, or null if unknown.

See Also:

• MathTransform.getTargetDimensions()

getParameters

@UML(identifier="parameter",
     obligation=OPTIONAL,
     specification=ISO_19111)
ParameterDescriptorGroup getParameters()

Returns the set of parameters. If the operation has no parameter, then this method shall return an empty group.

Returns:

the parameters, or an empty group (never null) if none.

See Also:

• SingleOperation.getParameterValues()

Convenience extension to OGC/ISO standard

The sequence if GeneralParameter is replaced by a ParameterGroup because it provides method for fetching parameters by their names.