How to speed up Matplotlib?

Question

I am new to Matplotlib and that's why there might be a more efficient way to run my program.

It is plotting a bunch of points with different colours (depending on some factors). It is constantly producing new pictures in a loop of the current colour state. Basically it looks like this:

import matplotlib.pyplot as plt

def getColour():
#calculate some stuff with x and y and the changing factors

while True: 
   fig = plt.figure(figsize=(17,10))
   plt.scatter(x, y , c=getColour())
   plt.show()
   plt.close(fig)

I was trying out clf() as well. However, it didn't change the pace at all. Does anyone have ideas? What am I doing wrong?

Thank you!

Edit: The target is to produce a picture each time it goes through the loop. Since my program is doing this quite slowly, my question is whether there is a way to make it run faster. I am working with python 2.7

Answer 1

Something like an animation:

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

ms_between_frames = 100
n_points = 100
x = np.arange(n_points, dtype=float) #EDIT
y = np.random.random(n_points)
z = np.random.random(n_points)

def getColour(x, y, z):
    c = np.empty((len(x),3))
    for i in range(len(x)):
        c[i] = [x[i]/n_points, z[i], 1.-z[i]]
    return c

def update(frame_number):
    global x, y
    z = np.random.random(n_points)
    c = getColour(x, y, z)
    graph.set_color(c)

fig = plt.figure(figsize=(17,10))
ax = fig.add_subplot(111)
graph = ax.scatter(x, y , c=getColour(x, y, z))
animation = FuncAnimation(fig, update, interval=ms_between_frames)
plt.show()

EDIT: made x hold floats so the division inside getColour would not return 0 (could also have made /float(n_points) )

By the way, it should be possible to define only one function to update the colours, depending on the arguments you require to do so, to avoid the call overhead.