Running Getis Ord using PySAL

getisord_example.py

from __future__ import print_function

# std lib
import os
import sys

# 3rd party
import pandas
import numpy 
numpy.random.seed(10)

from pysal.weights.Distance import DistanceBand
from getisord import G_Local

def main(input_points, headers, output_points):
    df = pandas.read_csv(input_points)
    df.columns = headers
    points = df[['x','y']].values.tolist()
    y = numpy.array(df['pop'].values.tolist())
    w = DistanceBand(points, threshold=100000)
    w.transform = "B"
    g = G_Local(y, w, star=True)
    results = zip(points, g.Zs)
    flat_results = map(lambda x: (x[0][0], x[0][1], x[1]), results)
    output_df = pandas.DataFrame(flat_results)
    output_df.columns = ('x', 'y', 'z_score')
    output_df.to_csv(output_points, index=False)

if __name__ == '__main__':
    input_points_csv = 'small_results.csv' 
    headers = ('year', 'x', 'y', 'pop') 
    output_points_csv = 'gedis_ord_result.csv' 
    main(input_points_csv, headers, output_points_csv)