matplotlib-users

[Matplotlib-users] Animating selected plot elements

[Alejandro W. <ale...@gm...>]

Hi:

I am trying to use this code http://tinyurl.com/44zcpfk (Scipy
cookbook) to make an animation where the background is fix and only a
line is updated. However, after executing the code, I only get a
window with an empty plot. Some debugging shows that the update_line
function is not being called.

I changed the use of numerix by numpy with respect to the original
code. Other than that is the same.

Any advice on how to fix the problem? Or may be this way is obsolete,
but all the animation examples I've found so far don't consider a
fixed background.

Alejandro.

Re: [Matplotlib-users] Animating selected plot elements

[Alejandro W. <ale...@gm...>]

On Mon, Apr 4, 2011 at 4:46 PM, Alejandro Weinstein
<ale...@gm...> wrote:
> Any advice on how to fix the problem? Or may be this way is obsolete,
> but all the animation examples I've found so far don't consider a
> fixed background.

Adding

import matplotlib
matplotlib.use('GTKAgg')

solved the problem.

But now I get this warning:

/usr/lib/pymodules/python2.6/matplotlib/backends/backend_gtk.py:621:
DeprecationWarning: Use the new widget gtk.Tooltip
  self.tooltips = gtk.Tooltips()

I am running Ubuntu 10.04, with MPL version 0.99.1.2-3ubuntu1, in case
that matter.

Alejandro.

Re: [Matplotlib-users] Animating selected plot elements

[Alejandro W. <ale...@gm...>]

On Mon, Apr 4, 2011 at 6:14 PM, Drew Frank <aj...@ic...> wrote:
> This will not address your immediate problem with update_line not
> being called, but if you want to animate something over a non-blank
> background you will soon run into another issue.  I posted here about
> that issue a while back:
> http://www.mail-archive.com/mat...@li.../msg19104.html
>
> To aid future web searchers, here is my final reply to that thread,
> which I accidentally sent to Benjamin Root rather than to the list:
> "The way the cookbook example is written (calling copy_from_background
> early), it will always copy a blank, white region -- even if
> non-animated elements have been plotted prior to the call.  This
> caused problems for me because I wanted to animate some patches on the
> top of a non-blank background, but calling restore_from_region just
> overwrote my background with white."
>
> Drew Frank

I also needed to use Frank's approach (described in the link above) to
make my animation works. Is it possible to fix the code in the
cookbook? I tried to edit the page but I am not allowed.

Alejandro.