FME Transformers: 2024.1

Categories
Geometries
Related Transformers
2DArcReplacer
2DEllipseReplacer
3DArcReplacer
ArcPropertyExtractor
ArcPropertySetter
ArcStroker
Creator
Curvefitter
EllipsePropertyExtractor
EllipsePropertySetter
Generalizer

ArcEstimator

Replaces geometry with an arc described by the first, middle, and last vertices of the input feature.

Jump to Configuration

Typical Uses

  • Undoing arc stroking on circular curves

  • Simplifying or smoothing

How does it work?

The ArcEstimator receives vector features with three or more vertices and replaces their geometry with arcs defined as Arc by 3 Points, using the first, last, and middle (median) vertices of the input line feature.

This transformer has no parameters.

Ellipses will be converted to arcs, and arcs are passed through unchanged.

For more information on arc geometry and types, see Arc.

Limitations

The ArcEstimator uses only three arbitrary points, and does not consider or weight any other vertices. It may not reliably reproduce the original geometry of curves that have been stroked.

It is most accurate for arcs that are circular (the primary and secondary radius are equal or nearly equal). Depending on the desired output, it may not be useful for interpolating curves along an irregular path.

Examples

Usage Notes

  • If the parameters for the desired arc are available as attributes on the feature (as Arc By Center Point), use a 2DArcReplacer or 3DArcReplacer.

  • The Curvefitter or a Generalizer using the Douglas With Arc Fitting algorithm are configurable and will generally produce better results for anything more complex than a simple circular arc.

Creating and Modifying Arcs, Circles, and Ellipses

These transformers work with arcs in a variety of ways.

Configuration

Input Ports

Output Ports

Parameters

This transformer has no parameters.

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.

Reference

Processing Behavior

Feature-Based

Feature Holding

No

Dependencies None
Aliases  
History  

FME Community

The FME Community is the place for demos, how-tos, articles, FAQs, and more. Get answers to your questions, learn from other users, and suggest, vote, and comment on new features.

Search for all results about the ArcEstimator on the FME Community.

 

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