33Multiprocess
44============
55
6- Demo of using multiprocessing for generating data in one process and plotting
7- in another.
6+ Demo of using multiprocessing for generating data in one process and
7+ plotting in another.
88
99Written by Robert Cimrman
1010"""
11-
1211from __future__import print_function
13- from six .moves import input
1412
1513import time
16- from multiprocessing import Process ,Pipe
1714import numpy as np
1815
19- import matplotlib
20- matplotlib .use ('GtkAgg' )
16+ from multiprocessing import Process ,Pipe
17+
18+ # This example will likely not work with the native OSX backend.
19+ # Uncomment the following lines to use the qt5 backend instead.
20+ #
21+ # import matplotlib
22+ # matplotlib.use('qt5Agg')
23+
2124import matplotlib .pyplot as plt
22- import gobject
2325
2426# Fixing random state for reproducibility
2527np .random .seed (19680801 )
2628
29+ ###############################################################################
30+ #
31+ # Processing Class
32+ # ================
33+ #
34+ # This class plots data it recieves from a pipe.
35+ #
36+
2737
2838class ProcessPlotter (object ):
2939def __init__ (self ):
@@ -55,18 +65,36 @@ def __call__(self, pipe):
5565
5666self .pipe = pipe
5767self .fig ,self .ax = plt .subplots ()
58- self .gid = gobject .timeout_add (1000 ,self .poll_draw ())
68+ timer = self .fig .canvas .new_timer (interval = 1000 )
69+ timer .add_callback (self .poll_draw ())
70+ timer .start ()
5971
6072print ('...done' )
6173plt .show ()
6274
75+ ###############################################################################
76+ #
77+ # Plotting class
78+ # ==============
79+ #
80+ # This class uses multiprocessing to spawn a process to run code from the
81+ # class above. When initialized, it creates a pipe and an instance of
82+ # ``ProcessPlotter`` which will be run in a separate process.
83+ #
84+ # When run from the command line, the parent process sends data to the spawned
85+ # process which is then plotted via the callback function specified in
86+ # ``ProcessPlotter:__call__``.
87+ #
88+
6389
6490class NBPlot (object ):
6591def __init__ (self ):
6692self .plot_pipe ,plotter_pipe = Pipe ()
6793self .plotter = ProcessPlotter ()
68- self .plot_process = Process (target = self .plotter ,
69- args = (plotter_pipe ,))
94+ self .plot_process = Process (
95+ target = self .plotter ,
96+ args = (plotter_pipe ,)
97+ )
7098self .plot_process .daemon = True
7199self .plot_process .start ()
72100
@@ -84,8 +112,8 @@ def main():
84112for ii in range (10 ):
85113pl .plot ()
86114time .sleep (0.5 )
87- input ('press Enter...' )
88115pl .plot (finished = True )
89116
117+
90118if __name__ == '__main__' :
91119main ()