geographicdata-from-csv/geomap-from-csv.py

# conda activate GEOGRAPHICMAP

# conda install basemap basemap-data-hires
# pip install pandas

# https://jakevdp.github.io/PythonDataScienceHandbook/04.13-geographic-data-with-basemap.html
# https://github.com/reddyprasade/DataSet-for-ML-and-Data-Science/blob/master/DataSets/california_cities.csv

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.basemap import Basemap
import pandas as pd

cities = pd.read_csv('california_cities.csv')

# Extract the data we're interested in
lat = cities['latd'].values
lon = cities['longd'].values
population = cities['population_total'].values
area = cities['area_total_km2'].values

# 1. Draw the map background
fig = plt.figure(figsize=(8, 8))
m = Basemap(projection='lcc', resolution='h', 
            lat_0=37.5, lon_0=-119,
            width=1E6, height=1.2E6)
m.shadedrelief()
m.drawcoastlines(color='gray')
m.drawcountries(color='gray')
m.drawstates(color='gray')

# 2. scatter city data, with color reflecting population
# and size reflecting area
m.scatter(lon, lat, latlon=True,
          c=np.log10(population), s=area,
          cmap='Reds', alpha=0.5)

# 3. create colorbar and legend
plt.colorbar(label=r'$\log_{10}({\rm population})$')
plt.clim(3, 7)

# make legend with dummy points
for a in [100, 300, 500]:
    plt.scatter([], [], c='k', alpha=0.5, s=a,
                label=str(a) + ' km$^2$')
plt.legend(scatterpoints=1, frameon=False,
           labelspacing=1, loc='lower left')
plt.title('California Cities')

plt.show()