matplotlib-users Mailing List for matplotlib

On Jan 21, 2007, at 11:04 AM, Allan Noriel Estrella wrote:
>
> does matplotlib already support wxPython 2.8?

I have not had the opportunity to test it with 2.8.  However, I am  
given to understand that it works.  The one caveat is that you cannot  
presently compile the WXAgg accelerator with 2.8.  Everything will  
still work without, but animation is slower.

Ken

does matplotlib already support wxPython 2.8?

>>>>> "Francesco" == Francesco Davide Calabrese <fd....@gm...> writes:

    Francesco> Hi, the following simple code (in Matlab syntax):

    Francesco> x1 = [5, 6] y1 = [3, 2] bar([1,2], [x1; y1])

    Francesco> produces a bar plot where two of the bars have a color
    Francesco> (let's say red) and the two other bars have another
    Francesco> color (let's say blue). I'd like to know whether it's
    Francesco> possible in matplotlib to plot the bars not simply with
    Francesco> a different color but with a different filling
    Francesco> pattern. So, for example, the blue bars filled with
    Francesco> vertical lines (or something else) and the red bars
    Francesco> filled with horizontal lines (or again something else).
    Francesco> Please, note that I'm not talking about the borders of
    Francesco> the bars. The reason why I need this feature is that I
    Francesco> have to clearly distinguish the bars also when they are
    Francesco> plotted in black and white, because many publications
    Francesco> can't be done in colors.

The postscript backend supports this -- we call it "hatching".
Unfortunately, the others do not yet.  See the example at
http://matplotlib.sf.net/examples/hatch_demo.py


One could be clever with "imshow" and create arrays that have the
hatching.  In the example I wrote below I created a custom bar chart
using gradient images.  By adding horizontal, vertical, or diangonal
lines to the arrays, or dots, one could support various hatching
schemes.  Here is the sample code for gradients that i wrote in
response to an earlier post:

   from pylab import figure, show, nx, cm

   def gbar(ax, x, y, width=0.5, bottom=0):
       X = [[.6, .6],[.7,.7]]
       for left,top in zip(x, y):
           right = left+width
           ax.imshow(X, interpolation='bicubic', cmap=cm.Blues,
                     extent=(left, right, bottom, top), alpha=1)

   fig = figure()

   xmin, xmax = xlim = 0,10
   ymin, ymax = ylim = 0,1
   ax = fig.add_subplot(111, xlim=xlim, ylim=ylim,
                        autoscale_on=False)
   X = [[.6, .6],[.7,.7]]

   ax.imshow(X, interpolation='bicubic', cmap=cm.copper,
             extent=(xmin, xmax, ymin, ymax), alpha=1)

   N = 10
   x = nx.arange(N)+0.25
   y = nx.mlab.rand(N)
   gbar(ax, x, y, width=0.7)
   ax.set_aspect('normal')
   show()

Ideally, we could do the work in Agg to support these hatched
images....

JDH

On Jan 21, 2007, at 8:21 AM, Allan Noriel Estrella wrote:
>
> i found this code snippet in one example in matplotlib
>
<snip>
>
> i just want to ask what does app = App(0) mean, why do we need 0  
> for an argument

It explicitly disables the redirection of sys.stdout and sys.stderr.

	http://www.wxpython.org/docs/api/wx.App-class.html#__init__

Ken

i found this code snippet in one example in matplotlib

class App(wx.App):

    def OnInit(self):
        'Create the main window and insert the custom frame'
        frame = CanvasFrame()
        frame.Show(True)

        return True

app = App(0)
app.MainLoop()

i just want to ask what does app = App(0) mean, why do we need 0 for an
argument