pylab matplotlib "show" waits until window closes

Question

I'd like to have the matplotlib "show" command return to the command line while displaying the plot. Most other plot packages, like R, do this. But pylab hangs until the plot window closes. For example:

import pylab
x = pylab.arange( 0, 10, 0.1)
y = pylab.sin(x)
pylab.plot(x,y, 'ro-')
pylab.show()   #  Python hangs here until the plot window is closed

I'd like to be able to view the plot while doing command line queries. I'm running Debian squeeze with python 2.6.6. My ~/.matplotlib/matplotlibrc contains

backend      : GTKAgg

Thanks!

Try using [IPython](http://ipython.org/) – David Z Mar 17 '12 at 21:36 — David Z, Mar 17 '12 at 21:36
you mean `ipython -pylab` to get the multithreading. – Andre Holzner Mar 17 '12 at 21:39 — Andre Holzner, Mar 17 '12 at 21:39

score 26 · Accepted Answer · answered Mar 17 '12 at 22:13

26

Add pylab.ion() (interactive mode) before the pylab.show() call. That will make the UI run in a separate thread and the call to show will return immediately.

answered Mar 17 '12 at 22:13

eudoxos

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Thank you. Works well. With `ion()`, the `show()` command is no longer needed. – Sullivan Mar 18 '12 at 04:08
2

It indeed immediately returns, but why the figure hangs there showing "Not Responding" – Sibbs Gambling Oct 08 '13 at 03:21

score 5 · Answer 2 · edited Oct 08 '13 at 04:45

5

You need to run it as

$ ipython --pylab

and run your code as

In [8]: x = arange(0,10,.1)

In [9]: y = sin(x)

In [10]: plot(x,y,'ro-')

Out[10]: [<matplotlib.lines.Line2D at 0x2f2fd50>]

In [11]:

This gives you the prompt for cases where you would want to modify other parts or plot more.

edited Oct 08 '13 at 04:45

tacaswell

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answered Mar 17 '12 at 22:06

Raghuram Onti Srinivasan

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pylab matplotlib "show" waits until window closes

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