Polygon Centroid: Center of gravity & Inner Centroid

PeterWilson — Sat, 11 Dec 2021 23:04:27 GMT

I thought I'd share the following with the community:

'''
Created on Apr 18, 2016


Centroid


of Polygon


@author: PeterW
'''
import arcpy
from arcpy.arcobjects.geometries import PointGeometry


input_fc = r"E:\Proposals\2016\what3words\Calcs.gdb\ftr_dwellings_zola_tm19"
output_fc = r"E:\Proposals\2016\what3words\Calcs.gdb\Centroids_Test15"




def coord_sys(input_fc):
    projection = arcpy.Describe(input_fc).spatialReference
    return projection


projection = coord_sys(input_fc)




def centroid(input_fc, output_fc):
    with arcpy.da.SearchCursor(input_fc, "SHAPE@XY") as scur:  # @UndefinedVariable
        centroid_coords = []
        for feature in scur:
            centroid_coords.append(feature[0])


    point = arcpy.Point()
    pointGeometryList = []


    for pt in centroid_coords:
        point.X = pt[0]
        point.Y = pt[1]


        pointGeometry = arcpy.PointGeometry(point, projection)
        pointGeometryList.append(pointGeometry)


    arcpy.CopyFeatures_management(pointGeometryList, output_fc)


centroid(input_fc, output_fc)

Centroid: Center of Gravity

'''
Created on Apr 18, 2016


Inner Centroid


of Polygon


@author: PeterW
'''
import arcpy


input_fc = r"E:\Proposals\2016\what3words\Calcs.gdb\ftr_dwellings_zola_tm19"
output_fc = r"E:\Proposals\2016\what3words\Calcs.gdb\Centroids_Test7"




def coord_sys(input_fc):
    projection = arcpy.Describe(input_fc).spatialReference
    return projection


projection = coord_sys(input_fc)




def inner_centroid(input_fc, output_fc):
    inner_centroid_geom = []
    with arcpy.da.SearchCursor(input_fc, "SHAPE@") as scur:  # @UndefinedVariable
        for feature in scur:
            inner_centroid_pnt = arcpy.PointGeometry(feature[0].labelPoint, projection)
            inner_centroid_geom.append(inner_centroid_pnt)
    arcpy.CopyFeatures_management(inner_centroid_geom, output_fc)


inner_centroid(input_fc, output_fc)

Centroid: Inner Centroid

Re: Polygon Centroid: Center of gravity & Inner Centroid

DanPatterson_Retired — Mon, 18 Apr 2016 22:07:52 GMT

Good catch..but I hate it that the 'magic' is hidden. Now can you determine the median as a representation of the centrality of a polygon (leave holes out of it for now)

topic Re: Polygon Centroid: Center of gravity & Inner Centroid in Python Questions

Polygon Centroid: Center of gravity & Inner Centroid

Re: Polygon Centroid: Center of gravity & Inner Centroid