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Smooth Line (Data Management) (ArcInfo and ArcEditor only)
Release 9.2 Last modified November 29, 2010	Print all topics in : "Tools"

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Smoothes a line to improve its aesthetic or cartographic quality.

Learn more about how Smooth Line works

Illustration

Smooth Line illustration

Usage tips

The Polynomial Approximation with Exponential Kernel (PAEK) algorithm produces smoothed lines; each may have more vertices than its source line. The tolerance you specify is the length of a "moving" path used in calculating the new vertices. The longer the length, the more smoothed the line. A small tolerance will result in a long processing time, so begin with a relatively large tolerance and a small number of lines.
The BEZIER_INTERPOLATION algorithm does not require any tolerance. If you are using the command line or scripting, you still need to enter zero in place of the smooth_tolerance.
When BEZIER_INTERPOLATION is used for shapefile output, it will produce lines very close to Bezier curves, since a shapefile cannot store true Bezier curves.
Both algorithms may introduce topological errors, such as line crossings, in the results. If you are not concerned about the topological errors, use the default, NO_CHECK option. If you want to know about the errors, use the FLAG_ERRORS option so that If any are found, a new field, SmoLnFlag, will be added to the output, storing a value of 1 for lines with topological errors and a value of zero to others.
Learn more about spatial reference and geoprocessing
The following environment settings affect this tool: XY tolerance, Extent, M domain, Coordinate system, Output has M values, Output has Z values, Default Z value, Output XY domain, workspace, and scratch workspace.

Command line syntax
An overview of the Command Line window
SmoothLine_management <in_features> <out_feature_class> <PAEK | BEZIER_INTERPOLATION> <tolerance> {FIXED_CLOSED_ENDPOINT | NO_FIXED} {NO_CHECK | FLAG_ERRORS}

Parameter	Explanation	Data Type
<in_features>	The line features to be smoothed.	Feature Layer
<out_feature_class>	The output feature class to be created.	Feature Class
<PAEK \| BEZIER_INTERPOLATION>	Specifies the line smoothing algorithm. PAEK — Stands for Polynomial Approximation with Exponential Kernel. It calculates a smoothed line that will not pass through the input line vertices. This is the default. BEZIER_INTERPOLATION — Fits Bezier curves between vertices. The resulting line passes through the vertices of the input line. This algorithm does not require a tolerance.	String
<tolerance>	Sets a tolerance used by the PAEK algorithm. A tolerance must be specified, and it must be greater than zero. You can specify a preferred unit; the default is the feature unit.	Linear unit
{FIXED_CLOSED_ENDPOINT \| NO_FIXED}	Specifies whether to preserve the endpoints for closed lines. This option works with the PAEK algorithm only. FIXED_CLOSED_ENDPOINT — Preserves the endpoint of a closed line. This is the default. NO_FIXED — Smoothes through the endpoint of a closed line.	Boolean
{NO_CHECK \| FLAG_ERRORS}	Specifies how the topological errors (possibly introduced in the process, such as line crossing) will be handled. NO_CHECK — Specifies not to check for topological errors. This is the default. FLAG_ERRORS — Specifies to flag topological errors, if any are found.	String

Data types for geoprocessing tool parameters

Command line example

smoothline contours smoothed_contours BEZIER_INTERPOLATION 0.0

Scripting syntax
About getting started with writing geoprocessing scripts
SmoothLine_management (in_features, out_feature_class, algorithm, tolerance, endpoint_option, error_option)

Parameter	Explanation	Data Type
in_features (Required)	The line features to be smoothed.	Feature Layer
out_feature_class (Required)	The output feature class to be created.	Feature Class
algorithm (Required)	Specifies the line smoothing algorithm. PAEK — Stands for Polynomial Approximation with Exponential Kernel. It calculates a smoothed line that will not pass through the input line vertices. This is the default. BEZIER_INTERPOLATION — Fits Bezier curves between vertices. The resulting line passes through the vertices of the input line. This algorithm does not require a tolerance.	String
tolerance (Required)	Sets a tolerance used by the PAEK algorithm. A tolerance must be specified, and it must be greater than zero. You can specify a preferred unit; the default is the feature unit.	Linear unit
endpoint_option (Optional)	Specifies whether to preserve the endpoints for closed lines. This option works with the PAEK algorithm only. FIXED_CLOSED_ENDPOINT — Preserves the endpoint of a closed line. This is the default. NO_FIXED — Smoothes through the endpoint of a closed line.	Boolean
error_option (Optional)	Specifies how the topological errors (possibly introduced in the process, such as line crossing) will be handled. NO_CHECK — Specifies not to check for topological errors. This is the default. FLAG_ERRORS — Specifies to flag topological errors, if any are found.	String

Data types for geoprocessing tool parameters

Script example

# Simplifying rivers followed by smoothing rivers

import arcgisscripting
gp = arcgisscripting.create()

# Set the workspace
gp.workspace = "d:/data/mapDB.mdb/hydrography"

# Simplifying rivers followed by smoothing rivers
gp.simplifyline("rivers", "rivers_simplified", "BEND_SIMPLIFY", "80", "RESOLVE_ERRORS")
gp.smoothline("rivers_simplified", "rivers_smoothed", "PAEK", "150")

Smooth Line (Data Management) (ArcInfo and ArcEditor only)

Command line example

Script example