CoordinateSystemExtractor

Retrieves the name of the feature's assigned FME coordinate system into an attribute.

Typical Uses

Identifying the coordinate system of a feature or dataset.

How does it work?

The CoordinateSystemExtractor receives any type of geometry and retrieves its FME coordinate system name, adding it to the features as an attribute.

If the input feature does not have a coordinate system defined, or if its coordinate system is not present in the FME coordinate systems file , the attribute will have an empty value.

Examples

Usage Notes

To convert the FME coordinate system name to another format such as EPSG number or OGC WKT, use the CoordinateSystemDescriptionConverter.
To manually assign a coordinate system, use the CoordinateSystemSetter.
For more information, see Working with Coordinate Systems.

Working With Coordinate System Transformers

FME inherently supports coordinate system transformations and reprojections.

Coordinate System Support and Reprojection

Coordinate systems generally have a name and a definition, and the syntax of that definition can vary greatly between both spatial data formats and other coordinate system libraries. Custom and local coordinate systems can also be defined in FME, further complicating matters. For in-depth information, see the Working With Coordinate Systems documentation.

Reprojections are generally done with the FME Reprojection Engine, which is based on the CS-Map coordinate system library. This default can be overridden on a per-workspace basis, using the Workspace Parameters > Translation > Reprojection Engine parameter, and set to Esri. Where appropriate, FME will use the Esri Reprojection Engine if it is selected there, with or without an Esri product being installed.

Coordinate System Support

These transformers perform various coordinate system-related tasks, but do not reproject the data.

CoordinateSystemDescriptionConverter	Looks up coordinate system names and definitions between FME’s internal format and common third-party and open source representations, storing the results as an attribute.
CoordinateSystemExtractor	Retrieves the name of the feature's assigned FME coordinate system into an attribute.
CoordinateSystemRemover	Removes the coordinate system from features, without modifying geometry or coordinates.
CoordinateSystemSetter	Assigns a specified coordinate system to features, without modifying geometry or coordinates.
LocalCoordinateSystemSetter	Assigns a specified local coordinate system to features, without modifying geometry or coordinates.

Coordinate System Reprojection

Different coordinate system libraries (engines) not only contain coordinate system definitions, they also have unique reprojection algorithms. FME’s generic reprojection transformers, in the first table below, default to using the FME (CS-Map) library.

A selection of other libraries is also available, some of which are specific to certain areas of the world or software platforms.

Inherent reprojections, as in a workspace with different input and output coordinate systems selected, default to using the FME (CS-Map) library.

If you are reprojecting explicitly with a transformer in the workspace, using library-specific transformers is recommended. In the case of CsmapReprojector versus the Reprojector (with default engine), the library may be identical, but the CSMapReprojector handles vertical coordinate calculations whereas the Reprojector does not.

Generic Reprojection Transformers

		Library
AttributeReprojector	Reprojects x and y coordinates stored as attributes from one coordinate system to another.	FME (default) or Esri
CommonLocalReprojector	Reprojects one or more features to a local coordinate system centered on the bounding box containing all features.	FME (default) or Esri
ReprojectAngleCalculator	Converts a given angle from one coordinate system to another.	FME (default) or Esri
ReprojectLengthCalculator	Converts a given length from one coordinate system to another.	FME (default) or Esri
Reprojector	Reprojects feature x and y coordinates from one coordinate system to another.	FME (default) or Esri

Library-Specific Reprojection Transformers (Recommended)

		Library (External Links)
CsmapAttributeReprojector	Reprojects x, y, and optionally z coordinates stored as attributes from one coordinate system to another using the CS-MAP library.	CS-Map
CsmapReprojector	Reprojects feature x, y, and optionally z coordinates from one coordinate system to another using the CS-Map library.	CS-Map
EsriReprojector	Reprojects feature coordinates from one coordinate system to another using the Esri reprojection library.	Esri
GridInQuestIIReprojector Great Britain Northern Ireland Republic of Ireland	Reprojects feature coordinates from one coordinate system to another using the Grid InQuestII engine from Ordnance Survey, for use in Great Britain, Ireland, and Northern Ireland.	Grid InQuestII
GtransAttributeReprojector Sweden	Reprojects coordinates stored as attributes from one coordinate system to another using the Gtrans reprojection engine from the National Land Survey of Sweden (Lantmäteriet).	Gtrans
GtransReprojector Sweden	Reprojects feature coordinates from one coordinate system to another using the Gtrans reprojection engine from the National Land Survey of Sweden (Lantmäteriet).	Gtrans
PROJAttributeReprojector	Reprojects coordinates stored as attributes from one coordinate system to another using the PROJ library.	PROJ
PROJReprojector	Reprojects feature coordinates from one coordinate system to another using the PROJ library.	PROJ
ReframeReprojector Switzerland	Reprojects feature coordinates from one coordinate system to another in Switzerland, using the Reframe library from the Federal Office of Topography (swisstopo).	REFRAME

Configuration

Input Ports

Output Ports

Parameters

Editing Transformer Parameters

Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.

Defining Values

There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.

How to Set Parameter Values

Using the Text Editor

The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.

Text Editor

Using the Arithmetic Editor

The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.

Arithmetic Editor

Conditional Values

Set values depending on one or more test conditions that either pass or fail.

Parameter Condition Definition Dialog

Content

Expressions and strings can include a number of functions, characters, parameters, and more.

When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.

Content Types

String Functions	These functions manipulate and format strings.
Special Characters	A set of control characters is available in the Text Editor.
Math Functions	Math functions are available in both editors.
Date/Time Functions	Date and time functions are available in the Text Editor.
Math Operators	These operators are available in the Arithmetic Editor.
FME Feature Functions	These return primarily feature-specific values.
FME Parameters	FME and workspace-specific parameters may be used.
Creating and Modifying User Parameters	Create your own editable parameters.

Dialog Options - Tables

Transformers with table-style parameters have additional tools for populating and manipulating values.

Table Tools

Row Reordering

Enabled once you have clicked on a row item. Choices include:

Add a row
Remove a row
Move current row up one
Move current row down one
Move current row to top
Move current row to bottom

Cut, Copy, and Paste

Enabled once you have clicked on a row item. Choices include:

Cut a row - delete and copy to clipboard
Copy a row to the clipboard
Paste a row from the clipboard

Cut, copy, and paste may be used within a transformer, or between transformers.

Filter

Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output.

Import

Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers.

Reset/Refresh

Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers.

Note: Not all tools are available in all transformers.

Reference

Processing Behavior	Feature-Based
Feature Holding	No
Dependencies	None
Aliases	CoordinateSystemFetcher
History

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Examples may contain information licensed under the Open Government Licence – Vancouver and/or the Open Government Licence – Canada.