Central Feature (Spatial Statistics)

Summary

Identifies the most centrally located feature in a point, line, or polygon feature class.

Learn more about how Central Feature works

Illustration

Usage

• The feature associated with the smallest accumulated distance to all other features in the dataset is the most centrally located feature; this feature is selected and copied to a newly created Output Feature Class.

• Calculations based on either Euclidean or Manhattan distance require projected data to accurately measure distances.

• For line and polygon features, feature centroids are used in distance computations. For multipoints, polylines, or polygons with multiple parts, the centroid is computed using the weighted mean center of all feature parts. The weighting for point features is 1, for line features is length, and for polygon features is area.

• Map layers can be used to define the Input Feature Class. When using a layer with a selection, only the selected features are included in the analysis.

• The Case Field is used to group features for separate Central Feature computations. The Case Field can be of integer, date, or string type.

• Self-potential is the distance or weight between a feature and itself. Often this weight is zero, but in some cases you may want to specify another fixed value or a different value for every feature (perhaps based on polygon size, for example).

Caution:

When using shapefiles, keep in mind that they cannot store null values. Tools or other procedures that create shapefiles from non-shapefile inputs may store or interpret null values as zero. This can lead to unexpected results. See also Geoprocessing considerations for shapefile output.

Syntax

CentralFeature_stats (Input_Feature_Class, Output_Feature_Class, Distance_Method, {Weight_Field}, {Self_Potential_Weight_Field}, {Case_Field})

Parameter	Explanation	Data Type
Input_Feature_Class	The feature class containing a distribution of features from which to identify the most centrally located feature.	Feature Layer
Output_Feature_Class	The feature class that will contain the most centrally located feature in the Input Feature Class.	Feature Class
Distance_Method	Specifies how distances are calculated from each feature to neighboring features. EUCLIDEAN_DISTANCE —The straight-line distance between two points (as the crow flies) MANHATTAN_DISTANCE —The distance between two points measured along axes at right angles (city block); calculated by summing the (absolute) difference between the x- and y-coordinates	String
Weight_Field (Optional)	The numeric field used to weight distances in the origin-destination distance matrix.	Field
Self_Potential_Weight_Field (Optional)	The field representing self-potential—the distance or weight between a feature and itself.	Field
Case_Field (Optional)	Field used to group features for separate central feature computations. The case field can be of integer, date, or string type.	Field

Code Sample

Central Feature Example (Python Window)

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

import arcpy
arcpy.env.workspace = r"C:\data"
arcpy.CentralFeature_stats("coffee_shops.shp", "coffee_CENTRALFEATURE.shp", "EUCLIDEAN_DISTANCE", "NUM_EMP", "#", "#")

Central Feature Example (Stand-alone Python script)

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

# Measure geographic distribution characteristics of coffee house locations weighted by the number of employees
 
# Import system modules
import arcpy
 
# Local variables...
workspace = "C:/data"
input_FC = "coffee_shops.shp"
CF_output = "coffee_CENTRALFEATURE.shp"
MEAN_output = "coffee_MEANCENTER.shp"
MED_output = "coffee_MEDIANCENTER.shp"
weight_field = "NUM_EMP"
 
try:
    # Set the workspace to avoid having to type out full path names
    arcpy.env.workspace = workspace
 
    # Process: Central Feature...
    arcpy.CentralFeature_stats(input_FC, CF_output, "EUCLIDEAN_DISTANCE", weight_field, "#", "#")
 
    # Process: Mean Center...
    arcpy.MeanCenter_stats(input_FC, MEAN_output, weight_field, "#", "#")

    # Process: Median Center...
    arcpy.MedianCenter_stats(input_FC, MED_output, weight_field, "#", "#")
 
except:
    # If an error occurred when running the tool, print out the error message.
    print arcpy.GetMessages()

Environments

Output Coordinate System, Current Workspace, Scratch Workspace, Qualified Field Names, Output has M values, Output has Z values, Default Output Z Value

Output Coordinate System

Feature geometry is projected to the Output Coordinate System prior to analysis.

Licensing Information

ArcView: Yes

ArcEditor: Yes

ArcInfo: Yes