Calculate Polygon Main Angle (Cartography)

Summary

Calculates the dominant angles of input polygon features and assigns the values to a specified field in the feature class.

Usage

• The dominant angle of a polygon is the angle of longest collection of segments that have similar orientation. This angle will be stored in the specified field in decimal degrees from true north.

• Use this tool to determine the trend of a polygon and use the resulting angle to orient symbology such as markers or hatch lines within the polygon. This tool is meant for primarily orthogonal polygons rather than organically-shaped ones.

Syntax

CalculatePolygonMainAngle_cartography (in_features, angle_field)

Parameter	Explanation	Data Type
in_features	The input polygon features.	Feature Layer
angle_field	The field that will be updated with the polygon main angle values.	Field

Code Sample

CalculatePolygonMainAngle tool Example (Python Window)

The following Python Window script demonstrates how to use the CalculatePolygonMainAngle tool in immediate mode.

import arcpy
from arcpy import env
env.workspace = "C:\data"

arcpy.CalculatePolygonMainAngle_cartography("cities", "poly_angle")

CalculatePolygonMainAngle tool Example (Stand-alone Python script)

This stand-alone script shows an example of using the CalculatePolygonMainAngle tool.

# Name: CalculatePolygonMainAngle_standalone_script.py
# Description: calculates an angle for a polygon based on the largest edge of the feature
 
# Import system modules
import arcpy
from arcpy import env

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

# Set local variables
in_features = "cities"
angle_field = "poly_angle"

# Execute Calculate Polygon Main Angle
arcpy.CalculatePolygonMainAngle_cartography(in_features, angle_field)

Environments

Cartographic Coordinate System

Licensing Information

ArcView: No

ArcEditor: Yes

ArcInfo: Yes