Matplotlib: django

Date:2011-07-12 (last modified), 2007-01-02 (created)
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Using MatPlotLib to dynamically generate charts in a Django web service

You need to have a working Django installation, plus matplotlib.

Example 1 - PIL Buffer

In [ ]:
# file charts.py
def simple(request):
    import random
    import django
    import datetime

    from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas
    from matplotlib.figure import Figure
    from matplotlib.dates import DateFormatter

    fig=Figure()
    ax=fig.add_subplot(111)
    x=[]
    y=[]
    now=datetime.datetime.now()
    delta=datetime.timedelta(days=1)
    for i in range(10):
        x.append(now)
        now+=delta
        y.append(random.randint(0, 1000))
    ax.plot_date(x, y, '-')
    ax.xaxis.set_major_formatter(DateFormatter('%Y-%m-%d'))
    fig.autofmt_xdate()
    canvas=FigureCanvas(fig)
    response=django.http.HttpResponse(content_type='image/png')
    canvas.print_png(response)
    return response

Since some versions of Internet Explorer ignore the content_type. The URL should end with ".png". You can create an entry in your urls.py like this:

In [ ]:
...
    (r'^charts/simple.png$', 'myapp.views.charts.simple'),
    ...

Section author: Unknown[90], Unknown[91], Unknown[92], Unknown[93], RalphMoore