Re: [Matplotlib-users] how to make matplotlib faster?

[Eric E. <ems...@ob...>]

Hi,

1. slow plot
2. cursor issue
3. key press event !
-------
1/ 

Here is the piece of code which is quite slow I think. Compared to 
pgplot this
is a factor of more than 10. It does first draw a default plot (0,1 ?) 
and then
overplot on it for each subplot.

for this particular case I have 10 subplots. The slices are made of 
about 10-20
points each only (stored in a 3D array which is  48x5x20 points).
I hope this answers the question. Sorry for the ''specifics''.

        for i in arange(ncoef) :
           subplot(nrow, 2, i+1)
           if i > 1 :
              temparray = self.Vcoef[indgal][i][:minind] / 
self.Vcoef[indgal][1][:minind]
              plot(self.Vrad[indgal][:minind], temparray, 'b-o', ms=4)
           else :
              plot(self.Vrad[indgal][:minind], 
self.Vcoef[indgal][i][:minind], 'b-o', ms=4)
           ylabel('$C_{%d'%i+'}$')

        for i in arange(ncoef) :
           j = i + ncoef
           subplot(nrow, 2, j+1)
           plot(self.Vrad[indgal][:minind], 
self.Vphi[indgal][i][:minind], 'b-o', ms=4)
           ylabel('$\phi_{%d'%i+'}$')

2/ the cursor issue and how to interact with it:
yes indeed the solution I took is close to what is shown in some examples.
I used a new class which I then use later on in interactive mode or not.
Below is a simple/shortened example of the structure I create by just 
transferring
the data (x,y,key, etc) to the cursor structure. I can then use : toto = 
cursor()
to have it working. (I in fact define several different cursor_* classes 
for different purposes).
So sorry if my mail sounded like ''I have found a new way...''.

class cursor :
   def __init__(self):
      print 'Class initialized'
      self.figure = Figure()
      self.canvas = get_current_fig_manager().canvas
      self.canvas.mpl_connect('button_press_event', self.on_click)
      self.x = 0
      self.y = 0
      self.button = 1

   def on_click(self, event):
      self.x = event.x
      self.y = event.y
      self.xd = event.xdata
      self.yd = event.ydata
      self.button = event.button
      ...

3/ key press event

>Currently key_press_event is not implemented (though mouse move and
>motion to capture and report key presses as event.key).  We added this
>because this is how we do the event handling across backends for the
>toolbar.  There are also some fixes in CVS to make disconnects work
>properly, eg in the tk backend.
>
>It would be fairly straightforward to add a key_press_event under the
>same framework.
>
>  
>
That WOULD be great since this is exactly what I needed. For example being
able to type ''h'' to make an horizontal cut of my image at the location 
corresponding
to the mouse position.... I do that easily with ppgplot for example.

-- 
===============================================================
Observatoire de Lyon                 ems...@ob...
9 av. Charles-Andre                      tel: +33 4 78 86 83 84
69561 Saint-Genis Laval Cedex            fax: +33 4 78 86 83 86
France               http://www-obs.univ-lyon1.fr/eric.emsellem
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