modelverse/interface/simple_plot/main.py

import matplotlib.pyplot as plt
import json
from matplotlib.animation import FuncAnimation
import threading

def read_data():
    try:
        return json.load(open("/tmp/values.pickle", 'r'))
    except:
        return (0.0, {})

def write_data(values):
    json.dump(values, open("/tmp/values.pickle", 'w'))

old_time, d = read_data()
l = raw_input()
time, key, value = l.split(" ")
time = float(time)
value = float(value)

if time <= old_time:
    # Overwrites current values, so flush
    d = {}

d.setdefault(key, []).append((time, value))

fig, ax = plt.subplots()
line, = ax.plot([], [])

try:
    def update_data():
        while 1:
            l = raw_input()
            plt.clf()
            time, key, value = l.split(" ")
            time = float(time)
            value = float(value)
            d.setdefault(key, []).append((time, value))

            keys = []
            for key in d:
                plt.plot([i[0] for i in d[key]], [i[1] for i in d[key]])
                keys.append(key)
            plt.legend(keys)

    def update_value(i):
        pass

    thrd = threading.Thread(target=update_data)
    thrd.daemon = True
    thrd.start()

    ani = FuncAnimation(fig, update_value, interval=1)
    plt.show()

except:
    print("Writing data...")
    write_data((time, d))