显示一些数字而不停止matplotlib中的计算

Question

Hi I would like to show a few figures in matplotlib without stopping calculations. I would like the figure to show up right after the calculations that concern it are finished for example:

import numpy as np
import pylab as py

x=np.linspace(0,50,51)
y=x
fig, axs = plt.subplots(1, 1)
cs = axs.plot(x, y)

now i want to show the plot without blocking the possibility to make some other calculations

plt.show(block=False)
plt.pause(5)

I create the second plot

y1=2*x
fig1, axs1 = plt.subplots(1, 1)
cs1 = axs1.plot(x, y1)

plt.show()

This works however the first freezes (after 5 secound pause which I added) until I call plt.show() at the end. It is crucial that the first figure shows and works, then after calculations another figure is added to it.

Answer 1

The following code should do what you want. I did this in an IPython Notebook.

from IPython import display
import matplotlib.pyplot as plt

def stream_plot(iterable, plotlife=10.):

        for I in iterable:
            display.clear_output(wait=True)
            output = do_calculations_on_i(I)
            plt.plot(output)
            display.display(plt.gca());
            time.sleep(plotlife); #how long to show the plot for

the wait=True will wait to clear the old plot until it has something new to plot, or any other output is printed.

I put the sleep in there so I can observe each plot before it is wiped away. This was useful for having to observe distributions for several entities. You may or may not need it for what you want to do.