CODEWITHSUNDEEP
pythonmatplotlib
suri
suri

Reputation: 347

Plotting graph without blocking execution in python

I want to plot graph inside a while loop, but execution is blocked after plt.show(G) command and resumes when i manually kill the plot window.

Code: 

while True:    
        print G.edges()
        Q = #coming from a function
        if Q > BestQ:
            nx.draw(G)
            plt.show(G)
        if G.number_of_edges() == 0:
            break

This is the output of G.edges() for two iterations:

[(0, 1), (1, 2), (1, 4), (1, 9), (2, 6), (3, 5), (5, 7), (5, 8), (5, 10)]
[(0, 1), (1, 4), (1, 9), (2, 6), (3, 5), (5, 7), (5, 8), (5, 10)]

How to make this continue after plotting???

Upvotes: 0

Views: 1089

Answers (1)

joaquin
joaquin

Reputation: 85683

You have to use interactive on and plt.draw.
Here you have a working example.
As I do not have your algorithm to generate your G graphs, I will draw constinuously the same network. Anyway, as each call to nx.draw(G) creates a different graph, you can see it updating the plot at each call. 

import matplotlib.pyplot as plt
import time
import networkx as nx

plt.ion()   # call interactive on

data = [(0, 1), (1, 2), (1, 4), (1, 9), (2, 6), (3, 5), (5, 7), (5, 8), (5, 10)]

# I create a networkX graph G
G = nx.Graph()
for item, (a, b) in enumerate(data):
    G.add_node(item)
    G.add_edge(a,b)

# make initial plot and set axes limits.
# (alternatively you may want to set this dynamically)
plot, = plt.plot([], [])
plt.xlim(-1, 3)
plt.ylim(-1, 3)

# here is the plotting stage.
for _ in range(10):           # plot 10 times
    plt.cla()                 # clear the previous plot
    nx.draw(G)
    plt.draw()
    time.sleep(2)             # otherwise it runs to fast to see

Upvotes: 1

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