ArcPropertyExtractor

Extracts the properties of arc geometry, storing the resulting values as attributes.

Jump to Configuration

Typical Uses

Making arc geometry properties accessible
Storing arc geometry properties for use elsewhere in a workspace

How does it work?

The ArcPropertyExtractor receives features with arc geometry and extracts their geometry properties into attributes.

Extracted properties include:

Primary Radius
Secondary Radius
Rotation
Start and Sweep Angle
Start X, Y and Z coordinates
End X, Y and Z coordinates
Center X, Y and Z coordinates

Values are calculated and extracted for all requested properties, regardless of the input arc geometry type.

To exclude an attribute, leave the parameter blank and it will not be added to the output features.

Feature geometry is unchanged.

Features without valid arc geometry are rejected, including ellipses.

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

Examples

Usage Notes

Paths with arc segments (such as the output of the Curvefitter) must be split into their components before using the ArcPropertyExtractor. See PathSplitter.

Creating and Modifying Arcs, Circles, and Ellipses

These transformers work with arcs in a variety of ways.

Arc Transformers Comparison

Transformer	Use this to...	Geometry Out	Z Coordinates
Creator	Create one or more new features with arc geometry (when Geometry Object is an arc type).	Arc by center point Arc by center point with ends Arc by 3 points Arc by bulge Ellipse (Arc by center point)	Supported
2DArcReplacer	Replace any existing feature’s geometry with a 2D arc.	Arc by center point	No
3DArcReplacer	Replace any existing feature’s geometry with a 3D arc.	Arc by center point	Yes, at center point
2DEllipseReplacer	Replace an existing feature’s geometry with a 2D ellipse or circle (closed arc).	Ellipse (Arc by center point)	No
ArcPropertySetter	Modify an existing arc or converts a point to an arc.	Arc by center point Arc by center point with ends Arc by 3 points	Supported, at center and/or ends
EllipsePropertySetter	Modify an existing ellipse (closed arc) or convert a point to an ellipse.	Ellipse (Arc by center point)	Supported, at center point
ArcPropertyExtractor	Extract the property values that describe an arc’s geometry and store them as attributes.	Arc by center point Arc by center point with ends Arc by 3 points Arc by bulge	Supported
EllipsePropertyExtractor	Extract the property values that describe an ellipse’s geometry and store them as attributes.	Ellipse (Arc by center point)	Supported
ArcStroker	Convert arcs and ellipses to lines or polygons by interpolating points along the arc.	Path Line Area	Supported
ArcEstimator	Replace geometry with an arc described by the first, middle, and last vertices of the input feature.	Arc by 3 points	Supported
Curvefitter	Replace lines or polygons with an optimal combination of line and arc segments, creating smooth curving lines.	Path Area Arc by bulge Line	Supported
Generalizer	Reduce point density on lines or polygons, fitting arcs where possible (When using Algorithm > Douglas With Arc Fitting (Generalize) ).	Path Area Arc by 3 points Line	Supported
MinimumSpanningCircleReplacer	Either replace an existing feature’s geometry with circle that contains all of its vertices or extract the circle property values into attributes.	Ellipse (Arc by center point)	No

Configuration

Input Ports

Output Ports

Note Feature order may change in relation to other output ports. Feature order per port is maintained.

Parameters

Output Attribute Names

Primary Radius	Name the attribute to contain the length of the primary radius in ground units of the feature’s coordinate system.
Secondary Radius	Name the attribute to contain the length of the secondary radius in ground units of the feature’s coordinate system.
Rotation	Name the attribute to contain the rotation angle. Rotation is measured in degrees from the horizontal axis to the primary axis in a counterclockwise direction.
Start Angle	Name the attribute to contain the starting angle of the arc, in degrees counterclockwise from the primary axis (horizontal plus or minus rotation).
Sweep Angle	Name the attribute to contain the sweep angle in degrees, which controls the duration of the arc. Positive sweep angles run counterclockwise beginning at the start angle and ending at the sum of the start and sweep angles. Negative sweep angles run clockwise.
Start X	Name the attribute to contain the x coordinate of the arc’s start point.
Start Y	Name the attribute to contain the y coordinate of the arc’s start point.
Start Z	Name the attribute to contain the z coordinate of the arc’s start point.
End X	Name the attribute to contain the x coordinate of the arc’s end point.
End Y	Name the attribute to contain the y coordinate of the arc’s end point.
End Z	Name the attribute to contain the z coordinate of the arc’s end point.
Center X	Name the attribute to contain the x coordinate of the arc’s center point.
Center Y	Name the attribute to contain the y coordinate of the arc’s center point.
Center Z	Name the attribute to contain the z coordinate of the arc’s center point.

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.

How to Set Parameter Values

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.

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

Table Tools

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

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.

For more information, see Transformer Parameter Menu Options.

Reference

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

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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.