- Prerequisites: You need to have the following installed to successfully run this example: Zope, Matplotlib (on top of Zope's Python), Python Image Library (PIL). And one more thing - probably every body does this right, but just in case - zope instance home directory has to be writable, for following to work.
- Create a file (e.g. mpl.py) in INSTANCEHOME\Extensions:
1 import matplotlib
2 matplotlib.use('Agg')
3 from pylab import *
4 from os import *
5 from StringIO import StringIO
6 from PIL import Image as PILImage
7 from matplotlib.backends.backend_agg import FigureCanvasAgg
8 def chart(self):
9 clf()
10 img_dpi=72
11 width=400
12 height=300
13 fig=figure(dpi=img_dpi, figsize=(width/img_dpi, height/img_dpi))
14 x=arange(0, 2*pi+0.1, 0.1)
15 sine=plot(x, sin(x))
16 legend(sine, "y=sin x", "upper right")
17 xlabel('x')
18 ylabel('y=sin x')
19 grid(True)
20 canvas = FigureCanvasAgg(fig)
21 canvas.draw()
22 size = (int(canvas.figure.get_figwidth())*img_dpi, int(canvas.figure.get_figheight())*img_dpi)
23 buf=canvas.tostring_rgb()
24 im=PILImage.fromstring('RGB', size, buf, 'raw', 'RGB', 0, 1)
25 imgdata=StringIO()
26 im.save(imgdata, 'PNG')
27 self.REQUEST.RESPONSE.setHeader('Pragma', 'no-cache')
28 self.REQUEST.RESPONSE.setHeader('Content-Type', 'image/png')
29 return imgdata.getvalue()
2. Then create an external method in ZMI (e.g. Id -> mplchart, module name -> mpl, function name -> chart).
3. Click the Test tab and you should see the sine plot.