ArcMap

Extend Line

Summary

Extends line segments to the first intersecting feature within a specified distance. If no intersecting feature is within the specified distance, the line segment will not be extended. Tool use is intended for quality control tasks such as cleaning up topology errors in features that were digitized without having set proper snapping environments.

Illustration

Extend Line illustration

Usage

  • If no Extend Length parameter is specified, segments will be extended to the first intersecting feature.

  • If the Extend to Extensions parameter is used, line segments can be extended to existing line features as well as other extended line segments within the specified extend length, forming intersections between two extensions.

  • A feature can be extended to itself, if it is the first intersecting feature.

  • If a feature layer or feature class with a selection is used as the input, only the selected features will be extended. All features within the layer or feature class will be used to assess if an extension can be performed, but only the selected features will be modified.

  • This tool will not change any feature attributes, except the managed geometry (length) fields in a personal, file, or enterprise geodatabase feature class.

Syntax

arcpy.edit.ExtendLine(in_features, {length}, {extend_to})
ParameterExplanationData Type
in_features

The line input features to be extended.

Feature Layer
length
(Optional)

The maximum distance a line segment can be extended to an intersecting feature.

Linear Unit
extend_to
(Optional)

Specifies whether line segments can be extended to other extended line segments within the specified extend length.

  • EXTENSION —Line segments can be extended to other extended line segments as well as existing line features. This is the default.
  • FEATURE —Line segments can only be extended to existing line features.
Boolean

Derived Output

NameExplanationData Type
out_feature_class

The updated input features.

Feature Class

Code sample

ExtendLine example 1 (Python window)

The following Python window script demonstrates how to use the ExtendLine function.

import arcpy
arcpy.env.workspace = "C:/data"
arcpy.ExtendLine_edit("majorrds.shp", "15 Feet", "EXTENSION")
ExtendLine example 2 (stand-alone script)

Clean up street centerlines that were digitized without having set proper snapping environments

# Name: ExtendLine.py
# Description:  Clean up street centerlines that were digitized without 
#               having set proper snapping environments.

# import system modules 
import arcpy

# Set environment settings
arcpy.env.workspace = "C:/data"

# Make backup copy of streets feature class, since modification with 
#  the Editing tools below is permanent
streets = "majorrds.shp"
streetsBackup = "C:/output/Output.gdb/streetsBackup"
arcpy.CopyFeatures_management(streets, streetsBackup)

# Trim street lines to clean up dangles
arcpy.TrimLine_edit(streets, "10 Feet", "KEEP_SHORT")

# Extend street lines to clean up dangles
arcpy.ExtendLine_edit(streets, "15 Feet", "EXTENSION")

Environments

Licensing information

  • Basic: No
  • Standard: Yes
  • Advanced: Yes

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