LineExtender

Extends line, arc, or path features at both ends by a specified length.

Typical Uses

Preparing geometry for further processing

How does it work?

The LineExtender receives features with line, arc, or path geometry and extends them at both ends by a specified length in ground units.

Extension angle is the same as the orientation of the line segment leading to the extension point (the first or last vertex). Arc geometry extensions are also straight lines, placed tangent to the arc.

Optionally, the angle of a number of segments back from the point of extension can be averaged. If the Segments to Average value is larger than the number of segments available on the feature, the entire feature orientation is averaged. For arc geometry, the segments are produced by default arc stroking which can produce unpredictable angles.

Two-point linear extensions are output individually as Beginning and End.

A Stretched geometry is also produced. If extended from a line segment, the start and end vertices of the input feature are moved to the end position of the extensions. If extended from an arc, the end vertices remain intact.

If the stretched geometry includes an arc or path, it is output as a path.

Output features receive the same attributes as the input feature.

Z coordinates are supported.

Segments to Average	Input	Beginning and End	Stretched
Default (1)
2
Default (1)
18

Usage Notes

This transformer may be useful in combination with the Snapper and Intersector to perform simple data cleaning.

Creating and Modifying Linear Features

These transformers work with lines in a variety of ways.

Line Transformers Comparison

	Function	Transformer Description
LineBuilder	Simple creation of lines from lines and/or points.	Connects sequential point and/or line features to create line or area geometry.
LineCombiner	Combining adjoining lines into longer lines or complex paths, with more advanced geometry handling options than the LineBuilder.	Connects line features that meet at common start or end points to create longer lines or paths.
PathBuilder	Combining arcs and lines into longer paths.	Connects sequential line and/or arc features to create path geometry, preserving input segments.
LineCloser	Converting linear features into areas.	Converts a linear feature to an area by connecting the end point to the start point.
LineExtender	Extending linear geometry.	Extends line, arc, or path features at both ends by a specified length.
Chopper	Chopping features into smaller features, breaking them at their existing vertices.	Chops line, arc, path, or area features into smaller features based on number of vertices or approximate length.
PathSplitter	Breaking a path into its component segments (lines and arcs).	Splits path geometry into its component line and/or arc segments.
Snipper	Shortening linear geometry.	Shortens linear geometry by cutting off the ends.
LineOnAreaOverlayer	Intersecting lines and areas.	Performs a line-on-area overlay, either splitting lines where they intersect area boundaries or subdividing areas where split by lines. Attributes may be shared between related lines and areas (spatial join).
LineOnLineOverlayer	Intersecting lines and lines.	Performs a line-on-line overlay in which all input lines are intersected against each other and resultant line features are created and output. Intersection points are turned into point features that can contain the merged list of attributes of the original intersected lines.
PointOnLineOverlayer	Finding where points lay on lines.	Performs a point-on-line overlay. Each input line is split at its closest place to any point within the specified point tolerance, and attributes may be shared between related points and lines (spatial join).

Configuration

Input Ports

Output Ports

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.

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

FME Community

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Search for all results about the LineExtender 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.