Description

A base class for transformation between two coordinate systems that have different datums.

This is the base class for classes used to transform coordinates between spatial references that have different datums. The inverse of the datum transformation, used to transform in the opposite direction, may be accessed using a member function.

A datum transformation has a name property intended to be suitable for display, such as when displaying a list of available transformations to an end user.

You can get a list of suitable transformations for a given input and output spatial reference using methods of the AGSTransformationCatalog class. Some transformations require that certain Projection Engine data files be present on the local file system. The property AGSDatumTransformation::missingProjectionEngineFiles indicates whether any of the files are missing. The complete list of necessary files is available using the AGSGeographicTransformationStep::projectionEngineFilenames or AGSHorizontalVerticalTransformationStep::projectionEngineFilenames properties.

Note: In order for any Projection Engine files to be found, the data location must be set first using the projectionEngineDirectory (AGSTransformationCatalog) property.

A datum transformation object is immutable

See also: AGSTransformationCatalog to find a list of suitable tranformations between two spatial references

Since: 100.2

Inheritance diagram for AGSDatumTransformation:

Instance Methods
(nullable AGSDatumTransformation *)	- inverse

(BOOL)	- isEqualToDatumTransformation:

Properties
AGSSpatialReference *	inputSpatialReference

BOOL	missingProjectionEngineFiles

NSString *	name

AGSSpatialReference *	outputSpatialReference

Method Documentation

◆ inverse

- (nullable AGSDatumTransformation *) inverse

Returns the inverse of this datum transformation.

Since: 100.2

◆ isEqualToDatumTransformation:

- (BOOL) isEqualToDatumTransformation: (AGSDatumTransformation *) other

Compares this spatial reference with the provided one for equality.

Parameters

other transformation to compare this one to.

Returns: boolean indicating whether the two transformation are equal

Since: 100.2

Property Documentation

◆ inputSpatialReference

- (AGSSpatialReference*) inputSpatialReference

readnonatomicstrong

The input spatial reference this transformation can be applied on.

Since: 100.2

◆ missingProjectionEngineFiles

- (BOOL) missingProjectionEngineFiles

readnonatomicassign

Indicates whether any data files needed by the Projection Engine is missing from the local file system.

Note: In order for any Projection Engine files to be found, the location must be set upon application startup using setProjectionEngineDirectory:error: (AGSTransformationCatalog) before using any other Runtime API.

Since: 100.2

◆ name

- (NSString*) name

readnonatomiccopy

The name of the datum transformation. For multi-step transformations, the name contains the concatenated names of each step's transformation, separated by a plus sign '+'. If the transformation is inverted, the name starts with a tilde (~).

Since: 100.2

◆ outputSpatialReference

- (AGSSpatialReference*) outputSpatialReference