ArcMap

Simplify Contours

Summary

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. Extraneous bends are composed of redundant vertices.

    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 tool with the PAEK algorithm.

  • The Scale parameter and tolerance values are used with Defense Mapping cartographic products.

  • Processing large datasets can 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.

    Learn more about generalizing large datasets using partitions

Syntax

arcpy.defense.SimplifyContours(Input_Contours, Scale)
ParameterExplanationData Type
Input_Contours

The input contours to be simplified.

Feature Layer
Scale

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

  • 1:5000 —The simplification tolerance will be 0.8 meters. The smoothing tolerance will be 12.8 meters.
  • 1:7500 —The simplification tolerance will be 1.2 meters. The smoothing tolerance will be 19.2 meters.
  • 1:10000 —The simplification tolerance will be 1.5 meters. The smoothing tolerance will be 25 meters.
  • 1:12500 —The simplification tolerance will be 2 meters. The smoothing tolerance will be 32 meters.
  • 1:25000 —The simplification tolerance will be 4 meters. The smoothing tolerance will be 64 meters.
  • 1:50000 —The simplification tolerance will be 8 meters. The smoothing tolerance will be 128 meters. This is the default.
  • 1:100000 —The simplification tolerance will be 16 meters. The smoothing tolerance will be 256 meters.
  • 1:250000 —The simplification tolerance will be 40 meters. The smoothing tolerance will be 640 meters.
  • 1:500000 —The simplification tolerance will be 80 meters. The smoothing tolerance will be 1280 meters.
  • 1:1000000 —The simplification tolerance will be 160 meters. The smoothing tolerance will be 2560 meters
String

Code sample

SimplifyContours example (Python window)

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

# 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

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

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