Count Rendering (Spatial Statistics)

Summary

Applies graduated circle rendering to a numeric field in a feature class.

Illustration

Usage

• The Count Rendering tool renders quantities as circles; circle size reflects value magnitudes. Tool output is a new layer file (.lyr).

• Rendering features quantitatively may reveal spatial patterns in the input count data.

• If no Maximum Field Value is provided, it is set to the largest value found in the Field to Render. Use the Maximum Field Value parameter when you want to compare several graduated circle maps; setting the same Maximum Field Value for a series of maps imposes a fixed circle size scaling even when the data ranges vary.

Legacy:
Beginning with the ArcGIS 10 release, this tool is a built-in tool (rather than a Visual Basic executable). While every effort was made not to break custom model and script tools developed prior to 10, there may be cases where older models that use this tool must be rebuilt in order for the model to run.

Syntax

CountRenderer_stats (input_feature_class, field_to_render, Output_Layer_File, number_of_classes, symbol_color, {maximum_field_value})

Parameter	Explanation	Data Type
input_feature_class	The feature layer containing count data to be rendered.	Feature Layer
field_to_render	The name of the field containing count data.	Field
Output_Layer_File	The new output layer file containing rendering information. You must include the .lyr extension as part of the file name.	Layer File
number_of_classes	The number of classes into which the input feature class will be classified.	Long
symbol_color	The color of the graduated circles. MANGO — BRIGHT_RED — DARK_GREEN — GREEN — DARK_BLUE — BRIGHT_PINK — LIGHT_YELLOW — SKY_BLUE —	String
maximum_field_value (Optional)	The maximum attribute value that will be rendered. Features with field values greater than this maximum value will not be drawn.	Double

Code Sample

CountRendering Example (Python Window)

The following Python Window script demonstrates how to use the CountRendering tool.

import arcpy
arcpy.env.workspace = "c:/data"
arcpy.CountRenderer_stats("autotheft_weighted.shp", "Count", "auto_weight_rendered.lyr", "5", "mango","#")

CountRendering Example (stand-alone Python script)

The following stand-alone Python script demonstrates how to use the CountRendering tool.

# Convert incident data to weighted point data and render
 
# Import system modules
import arcpy, sys, string, os
 
# Local variables...
workspace = "C:/data"
input = "AutoTheft.shp"
input_weighted = "autotheft_weighted.shp"
results_field = "Count"
input_weighted_rendered = "auto_weight_rendered.lyr"
 
try:
    # Set the current workspace (to avoid having to specify the full path to the feature classes each time)
    arcpy.env.workspace = workspace
 
    # Process: Collect Events...
    arcpy.CollectEvents_stats(input, input_weighted, results_field)
 
    # Process: Count Rendering...
    arcpy.CountRenderer_stats(input_weighted, results_field, input_weighted_rendered, "5", "MANGO", "#")
 
except:
    # If an error occurred when running the tool, print out the error message.
    print arcpy.GetMessages()

Environments

Current Workspace, Scratch Workspace

Licensing Information

ArcView: Yes

ArcEditor: Yes

ArcInfo: Yes