Contour List (Spatial Analyst Tools)

Summary

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

Usage

Contours do not extend beyond the spatial extent of the raster, and they are not generated in areas of NoData. Edgematch adjacent contour inputs into a continuous feature dataset first. 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 those areas. Negative contour intervals are not allowed.
The contour values do not need to be sorted in order.
The Contour type parameter specifies whether the tool will produce either contour lines or polygons. For example, if you have a raster with values between 0 and 575 and your contour values are 250 and 299, the following are the various output feature classes that will be created:
- Contour ('CONTOUR' in Python)—Lines at 250 and 299
- Contour polygon ('CONTOUR_POLYGON' in Python)—Nonoverlapping polygons between 0-250, 250-299, and 299-575
Smoother but less accurate contours can be obtained by preprocessing the input raster using the Focal Statistics tool with the Mean option or the Filter tool with the Low option.
By default, this tool will use multicore processors if available. The maximum number of cores that can be used is four.

To use fewer cores, use the Parallel Processing Factor environment setting.
If the Extent environment is specified and the lower left corner of the output extent does not match any cell corner of the input raster, a shift of the cell alignment of the input raster will occur during processing to match the specified extent. This shift will cause a resampling of the input raster using the bilinear method. Consequently, the output features will shift as well, and the resultant output features may not overlay the original input raster exactly. You can avoid this shift by using the input raster for the Snap Raster environment.
See Analysis environments and Spatial Analyst for additional details on the geoprocessing environments that apply to this tool.

Label	Explanation	Data type
Input raster	The input surface raster.	Raster Layer
Output contour features	The output contour polyline features.	Feature Class
Contour values	List of z-values for which to create contours.	Double
Contour type (Optional)	Specifies the type of output. The output can represent the contours as either lines or polygons. Contour—A polyline feature class of contours (isolines). This is the default. Contour polygon—A polygon feature class of filled contours.	String

ContourList(in_raster, out_polyline_features, contour_values, {contour_type})

Name	Explanation	Data 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
contour_type (Optional)	Specifies the type of output. The output can represent the contours as either lines or polygons. `CONTOUR`—A polyline feature class of contours (isolines). This is the default. `CONTOUR_POLYGON`—A polygon feature class of filled contours.	String

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"

# Run ContourList
ContourList(inRaster, outContours, contourIntervalList)

Environments

Auto Commit, Cell Size, Cell Size Projection Method, Current Workspace, Default Output Z Value, Extent, Geographic Transformations, M Resolution, M Tolerance, Output CONFIG Keyword, Output Coordinate System, Output has M values, Output has Z values, Output M Domain, Output XY Domain, Output Z Domain, Parallel Processing Factor, Scratch Workspace, Snap Raster, Z Resolution, Z Tolerance

Licensing information