How to create a simple line graph in Python

Question

Can someone please tell me if there is a way of making a constantly updating line graph in Python? Thanks for any answers.

Answer 1

First of all you will need to install some dependencies: matplotlib and numpy.

The first option is to use matplotlib animation like in this example:

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation


def update_line(num, data, line):
    line.set_data(data[..., :num])
    return line,

fig1 = plt.figure()

data = np.random.rand(2, 25)
l, = plt.plot([], [], 'r-')
plt.xlim(0, 1)
plt.ylim(0, 1)
plt.xlabel('x')
plt.title('test')
line_ani = animation.FuncAnimation(fig1, update_line, 25, fargs=(data,l),interval=50, blit=True)
plt.show()

A more mathematical option is this one:

import matplotlib.pyplot as plt
import numpy as np
import time 

x = np.linspace(0, 1, 20)
y = np.random.rand(1, 20)[0]


plt.ion()
fig = plt.figure()
ay = fig.add_subplot(111)
line1, = ay.plot(x, y, 'b-') 

for i in range(0,100):
    y = np.random.rand(1, 20)[0]
    line1.set_ydata(y)
    fig.canvas.draw()
    time.sleep(0.1)

I hope this is what you were searching for.