FME Transformers: 2024.1

Calculated Values
Related Transformers


Converts a given angle from one coordinate system to another.

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Typical Uses

  • Determining angles for text and symbol rotation
  • Reprojecting angles stored as attribute values

How does it work?

The ReprojectAngleCalculator receives features with geometry and reprojects a given angle from one coordinate system to another.

The transformer starts with two points. One is the first coordinate of the input feature’s geometry, and the second is calculated from that point using the Original Line Angle and Original Line Length. Both of these points are reprojected from the Source Coordinate System to the Destination Coordinate System. A new angle is calculated from the reprojected points and added to the output feature as an attribute value.

The Original Line Angle may be provided as an attribute value, constant value, expression, user parameter, or conditional value.

Original Line Length is also required to perform the calculation, in the Source Coordinate System’s ground units. The length may be provided as an attribute, expression, constant, parameter, or conditional value. A length of one (1) is often appropriate for calculating rotation around a point, such as text and symbol rotation angles.

Both the Source and Destination Coordinate Systems must be specified explicitly.

Reprojections are generally performed using the FME (CS-Map) library, however, this transformer will honor the Workspace Parameter Reprojection Engine, and will use the Esri Reprojection Engine if it is selected there, with or without an Esri product being installed.

Z values are not supported.

This transformer assumes all coordinate systems are Cartesian.


Usage Notes

  • This transformer requires that features have geometry to provide an initial coordinate. Non-spatial features will not produce valid output. To create geometry for non-spatial data with coordinates as attributes, consider using a VertexCreator.

Working With Coordinate System Transformers

FME inherently supports coordinate system transformations and reprojections.


Input Ports

Output Ports


Editing Transformer Parameters

Transformer parameters can be set by directly entering values, using expressions, or referencing other elements in the workspace such as attribute values or user parameters. Various editors and context menus are available to assist. To see what is available, click beside the applicable parameter.

For more information, see Transformer Parameter Menu Options.


Processing Behavior


Feature Holding


Dependencies None

FME Community

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