ArcMap

Simplify Contours

Summary

Defense Mapping production tool that simplifies contours for use in cartographic products. This tool preserves the essential shape of a contour by eliminating extraneous bends.

Usage

  • This tool modifies the input contours. You cannot undo this operation.

  • This tool first identifies redundant vertices, which are those that lie within a minimum allowable distance, or tolerance. Tolerance depends on the Scale parameter. This is accomplished in the tool using the Simplify Line tool with the POINT_REMOVE algorithm.

    This tool then runs a smoothing algorithm, which is also dependent on the Scale parameter. This is accomplished in the tool using the Smooth Line geoprocessing tool with the PAEK algorithm.

  • Extraneous bends are composed of redundant vertices. This tool identifies redundant vertices as those that lie within a minimum allowable distance, or tolerance. Tolerance depends on the Scale parameter.

  • The Scale parameter and tolerance values are designed for use with Defense Mapping cartographic products.

  • Processing large datasets may exceed memory limitations. This is true with contours over large areas of interest, because the features have so many vertices. In such cases, consider processing input data by partition by identifying a relevant polygon feature class in the Cartographic Partitions environment setting. Portions of the data, defined by partition boundaries, will be processed sequentially. The resulting feature class will be seamless and consistent at partition edges. See Generalizing large datasets using partitions for more information.

Syntax

SimplifyContours(Input_Contours, Scale)
ParameterExplanationData Type
Input_Contours

The input contours to be simplified.

Feature Layer
Scale

Determines a simplification and smoothing tolerance. Tolerance specifies a minimum allowable distance between vertices. The tool removes vertices that lie within this tolerance.

  • 1:5000 —Simplification tolerance is .8 meters. Smoothing tolerance is 12.8 meters.
  • 1:7500 —Simplification tolerance is 1.2 meters. Smoothing tolerance is 19.2 meters.
  • 1:12500 —Simplification tolerance is 2 meters. Smoothing tolerance is 32 meters.
  • 1:25000 —Simplification tolerance is 4 meters. Smoothing tolerance is 64 meters.
  • 1:50000 —Simplification tolerance is 8 meters. Smoothing tolerance is 128 meters. This is the default.
  • 1:100000 —Simplification tolerance is 16 meters. Smoothing tolerance is 256 meters.
  • 1:250000 —Simplification tolerance is 40 meters. Smoothing tolerance is 640 meters.
  • 1:500000 —Simplification tolerance is 80 meters. Smoothing tolerance is 1280 meters.
  • 1:1000000 —Simplification tolerance is 160 meters. Smoothing tolerance is 2560 meters
String

Code sample

SimplifyContours example (Python window)

The following code sample demonstrates how to use the SimplifyContours tool.

# set gp environment
arcpy.env.workspace="C:/data"

# variables for tool
inputContours="mgcp.gdb/mgcp/contours"
mapScale="1:12500"

# execute the tool
arcpy.SimplifyContours_defense(inputContours,mapScale)

Environments

Licensing information

  • ArcGIS Desktop Basic: No
  • ArcGIS Desktop Standard: Requires Defense Mapping
  • ArcGIS Desktop Advanced: Requires Defense Mapping

Related topics