Eliminate (Coverage)

Summary

Merges the selected polygons with neighboring polygons if they have the largest shared border or the largest area.

Eliminate is often used to remove sliver polygons created during polygon overlay or buffering. With the LINE option, Eliminate merges selected arcs separated by pseudo nodes into single arcs.

Learn more about how Eliminate works

Illustration

Eliminate illustration

Usage

Syntax

Eliminate_arc (in_cover, out_cover, info_express, {polygon_boundary}, {feature_type}, {selection_file}, {polygon_option})
ParameterExplanationData Type
in_cover

The coverage whose selected polygons or arcs will be merged into neighboring features.

Coverage
out_cover

The new coverage with all the selected sliver polygons merged into larger features. There should be a smaller number of polygons than the Input Coverage contains.

Coverage
info_express
[info_express,...]

An INFO query containing one or more logical expressions to select features from the input coverage.

  • Reselect—Reduces the selected set of records with a selection expression to those that meet its criteria. If no selection expression follows, the selected set will be empty.
  • Aselect—Adds unselected records that meet the selection expression criteria to the currently selected set. If no selection expression follows, the selected set will contain all features.
  • Nselect—Reverses the current selection to the unselected set.
ArcInfo Expression
polygon_boundary
(Optional)

Ensures that polygons along the coverage boundary are not altered.

  • NO_KEEP_EDGEAllows the elimination of outer polygon boundaries. This is the default.
  • KEEP_EDGEIs only used with the POLYGON option. Any polygon which is a neighbor of the background polygon will not be eliminated when KEEP_EDGE is specified.
Boolean
feature_type
(Optional)

The feature class(es) to be eliminated in the Output Coverage. This parameter is only used for polygon coverages.

  • POLYPolygon features will be eliminated; an AAT will not be created for the Output Coverage.
  • LINELine features will be eliminated; a PAT will not be created for the Output Coverage.
String
selection_file
(Optional)

A Selection File is a preexisting file that identifies which features will be used.

File
polygon_option
(Optional)

Specifies which method will be used for eliminating polygons. This parameter is only used for polygon coverages.

  • BORDERMerges a selected polygon with a neighboring unselected polygon by dropping an Arc. The neighboring polygon is the one with the longest shared border. This is the default and the way Eliminate worked with the POLY option in all pre-6.1.1 releases.
  • AREAMerges a selected polygon with a neighboring unselected polygon by dropping an Arc. The neighboring polygon is the one with the largest area.
String

Code Sample

Eliminate example (stand-alone script)

The following stand-alone script demonstrates how to remove sliver polygons from a coverage.

# Name: Eliminate_Example.py
# Description: Removes sliver polygons from an input coverage
# Requirements: ArcInfo Workstation
# Author: ESRI

# Import system modules
import arcpy
from arcpy import env

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

# Set local variables
inCover = "txlnd"
outCover = "C:/output/texout"
infoExpress = "reselect AREA LE 68000"
polygonBoundary = "KEEP_EDGE"
featureType = "POLY"
polygonOption = "AREA"

# Execute Eliminate
arcpy.Eliminate_arc(inCover, outCover, infoExpress, polygonBoundary, 
                    featureType, "", polygonOption)

Environments

Related Topics

Licensing Information

ArcView: No
ArcEditor: No
ArcInfo: Requires ArcInfo Workstation installed

Published 6/8/2010