Matplotlib - an odd problem
koranthala at gmail.com
Thu Jun 25 05:25:26 CEST 2009
On Jun 25, 2:55 am, Jean-Paul Calderone <exar... at divmod.com> wrote:
> On Wed, 24 Jun 2009 11:38:02 -0700 (PDT), koranthala <koranth... at gmail.com> wrote:
> >I am using Matplotlib with Django to display charts on the web page.
> >I am facing an odd problem in that, everytime I do a refresh on the
> >web page, the image darkens - and the text becomes little unreadable.
> >5/6 refreshes later, the text becomes completely unreadable.
> >Since I am using Django test server, the same process is being used.
> >i.e. every refresh does not create a new process. When I tried killing
> >the process, the image again cleared.
> >So I think it is sort of memory leak or a saved value which is messing
> >up something.
> >But I cannot seem to find the issue at all.
> >The code is as follows -
> >import pylab
> >from cStringIO import StringIO
> >def print_pie_chart(request):
> > labels = 'Frogs', 'Hogs', 'Dogs', 'Logs'
> > data = [15,30,45, 10]
> > pylab.figure(1, figsize=(2,2))
> > ax = pylab.axes([0.1, 0.1, 0.8, 0.8])
> > pylab.pie(data, explode=None, labels=labels, autopct='%1.1f%%',
> > out = StringIO()
> > pylab.savefig(out, format="PNG")
> > out.seek(0)
> > response = HttpResponse()
> > response['Content-Type'] = 'image/png'
> > response.write(out.read())
> > return response
> >Can anyone help me out here?
> Your code redraws over the same graph over and over again. You need to
> create a new graph each time you want to draw something new. It took me
> ages (and help) to figure out how the non-global APIs in matplotlib.
> Here's an example:
> from matplotlib.figure import Figure
> from matplotlib.axes import Axes
> from matplotlib.backends.backend_gtkagg import FigureCanvasGTKAgg as FigureCanvas
> fig = Figure(figsize=(9, 9), dpi=100)
> axe = Axes(fig, (0, 0, 1.0, 1.0))
> canvas = FigureCanvas(fig)
> canvas.set_size_request(640, 480)
> Hope this helps,
Thank you Jean-Paul
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