ArcMap

Contour List

Available with Spatial Analyst license.

Summary

Creates a feature class of selected contour values from a raster surface.

Learn more about how Contouring works

Usage

  • Contours do not extend beyond the spatial extent of the raster, and they are not generated in areas of NoData; therefore, adjacent contour inputs should first be edgematched into a continuous feature dataset. As an alternative to edgematching, you can merge the adjacent rasters before computing contours.

  • Contours can be generated in areas of negative raster values. The contour values will be negative in such areas. Negative contour intervals are not allowed.

  • The contour values do not need to be sorted in order.

  • Smoother but less accurate contours can be obtained by preprocessing the input raster with a Focal Statistics operation with the MEAN option or the Filter tool with the LOW option.

  • If the output extent is changed from the default, Resampling of the input raster may occur. To avoid this, and to ensure consistent results, set the Snap Raster environment to be the input raster.

  • When the input raster needs to be resampled, the Bilinear technique will be used. An example of when an input raster may be resampled is when the output coordinate system, extent, or cell size is different from that of the input.

  • See Analysis environments and Spatial Analyst for additional details on the geoprocessing environments that apply to this tool.

Syntax

ContourList (in_raster, out_polyline_features, contour_values)
ParameterExplanationData Type
in_raster

The input surface raster.

Raster Layer
out_polyline_features

The output contour polyline features.

Feature Class
contour_values
[contour_value,...]

List of z-values for which to create contours.

Double

Code sample

ContourList example 1 (Python window)

This example creates contours for three elevation values from an Esri Grid raster and outputs them as a shapefile.

import arcpy
from arcpy import env  
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
ContourList("elevation", "C:/sapyexamples/output/outcontourlist.shp", [600, 935, 1237.4])
ContourList example 2 (stand-alone script)

This example creates contours for three elevation values from an Esri Grid raster and outputs them as a shapefile.

# Name: ContourList_Ex_02.py
# Description: CCreates contours or isolines based on a list of contour values.
# Requirements: Spatial Analyst Extension

# Import system modules
import arcpy
from arcpy import env
from arcpy.sa import *

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

# Set local variables
inRaster = "elevation"
contourIntervalList = [600, 935, 1237.4]
outContours = "C:/sapyexamples/output/outcontourlist02.shp"

# Check out the ArcGIS Spatial Analyst extension license
arcpy.CheckOutExtension("Spatial")

# Execute ContourList
ContourList(inRaster, outContours, contourIntervalList)

Environments

Licensing information

  • ArcGIS Desktop Basic: Requires Spatial Analyst or 3D Analyst
  • ArcGIS Desktop Standard: Requires Spatial Analyst or 3D Analyst
  • ArcGIS Desktop Advanced: Requires Spatial Analyst or 3D Analyst

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