A while ago I had exactly the same problem. I was running a script that create a lot of figures and saved them (as .png and .eps files) for viewing later (so not using the interactive viewing feature from pyplot). If I remember well, there was also a problem with the close() statement leaving some stuff in memory. Unfortunately I don't remember how the details went and how it got fixed. I guess I should have used the mailing list or created a bug report.
Anyway, when I need to generate a massive amount of figures these days I bypass the pyplot interface completely and go straight for the matplotlib API (at least as far as I understand this approach myself). When using pyplot, some figure tweaks did not persist upon saving, but that might as well have been due to my limited matplotlib knowledge. The procedure was inspired by this blog post: http://sjohannes.wordpress.com/2010/06/11/using-matplotlib-in-a-web-application/ and goes as follows: from matplotlib.figure import Figure # dependent on the backend you use from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigCanvas # set figure size, dpi and initiate a workable fig object fig = Figure(figsize=(figsize_x, figsize_y), dpi=dpi) canvas = FigCanvas(fig) fig.set_canvas(canvas) # tweak white spacings fig.subplots_adjust(left=wsleft, bottom=wsbottom, right=wsright, top=wstop, wspace=wspace, hspace=hspace) # big main title fig.suptitle(grandtitle, size='x-large') # create a subplot ax = fig.add_subplot(nr_rows, nr_cols, plot_nr) # do all your plotting stuff here on ax # save the figure and close fig.savefig('/path/to/figure/figname.png') canvas.close() fig.clear() If interested, I can give you a more elaborate and working example of which parameters I tune how exactly. Regards, David On 23/03/12 19:45, Eric Firing wrote: > On 03/23/2012 08:05 AM, Albert Kottke wrote: >> I am having problems clearing figures from memory. After saving the >> figure, I use pyplot.close() on the figure handle and then del all of >> the data and figure, as shown here: >> >> fig.savefig('plots/%(record_id)05i' % recording) >> plt.close(fig) >> >> del accel, fourier_amp, fig, time, disp >> gc.collect() >> >> Despite this, the figures don't appear to be closing. I am trying to >> make 30k plots and I have to kill script every couple thousand and >> restart because I run out of memory. >> >> Any suggestions? > You are running a standalone script, correct? Make sure you are using > only the agg backend. Before the first import of pyplot, do > > import matplotlib > matplotlib.use("agg") > > I don't know if that will help, but it can't hurt. > > You might find matplotlib.cbook.report_memory() to be useful in tracking > down the problem. > > Eric > >> >> Albert >> >> ------------------------------------------------------------------------------ >> This SF email is sponsosred by: >> Try Windows Azure free for 90 days Click Here >> http://p.sf.net/sfu/sfd2d-msazure >> _______________________________________________ >> Matplotlib-users mailing list >> Matplotlib-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/matplotlib-users > > ------------------------------------------------------------------------------ > This SF email is sponsosred by: > Try Windows Azure free for 90 days Click Here > http://p.sf.net/sfu/sfd2d-msazure > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users ------------------------------------------------------------------------------ This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
