chart.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import csv
import urllib2
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.image as image
import pylab
from PIL import Image

DATA_URL = "https://docs.google.com/spreadsheets/d/19infjiXqudq86oL8XT-1SEtP1-QrRMrBXKfimrVPSl8/pub?gid=0&single=true&output=csv"
START_YEAR = 1600
END_YEAR = 2017

response = urllib2.urlopen(DATA_URL)
cr = csv.reader(response)

next(cr) # Skips first line

wars = [] # Will contain all data

for row in cr:
    wars.append({"start": int(row[1]), "end": int(row[2]), "casualties": int(row[3]), "duration": int(row[2]) - int(row[1])})

# Loops through all years
years = [] # For intensity
years_bool = [] # For plotting

for year in range(0, END_YEAR - START_YEAR):

	year_actual = year + START_YEAR
	
	years.append(0) # init the year
	years_bool.append(0)

	# Loops through the wars and get avg casualties per year
	for war in wars:
		if war["start"] <= year_actual and war["end"] >= year_actual:
			years_bool[year] = 1
			years[year] += (war["casualties"] / war["duration"])

# Makes the graph
figure = plt.figure(1, figsize=(10, 5))
ax = plt.subplot(111)
bars = ax.bar(range(0, END_YEAR - START_YEAR), years_bool, 1, linewidth = 0)

year = 0
for bar in bars:
	opacity = 0
	opacity = round(years[year] / 1e4) / 100

	year_actual = year + START_YEAR

	if opacity > 1:
		opacity = 1
	bar.set_color((0,0,0,opacity)) # Sets intensity, max opacity for 1m casualties per year

	# Special case for 1957
	if year_actual == 1957:
		bar.set_color('#0D4F8B')

	print year_actual, years[year], opacity, bar.get_facecolor()
	year += 1

# Set ticks to actual years
ticks = np.arange(0, END_YEAR - START_YEAR, 100)
labels = np.arange(START_YEAR, END_YEAR, 100)
plt.xticks(ticks, labels)
ax.set_ylim([0,1])

# Removes everything, makes thick frame
ax.spines['right'].set_linewidth(5)
ax.spines['top'].set_linewidth(5)
ax.spines['bottom'].set_linewidth(5)
ax.spines['left'].set_linewidth(5)
plt.tick_params(
    axis='both',         
    which='both',      
    bottom='off',      
    top='off',
    left= 'off',
    right='off',         
    labelleft='off')

# Makes layout more legible
figure.tight_layout()

# Saves image
pylab.savefig('graph.png',dpi=80)
plt.close(figure)