Re: [Matplotlib-users] Animation with copy_from_bbox / restore_region

Yes, I'm using the line2D.set_data function along with the draw_artist
(and a blit). I haven't made a line collection object since I don't
think it will speed it up by around the factor 5 that I want. I'll try
that but I still think that the ability to grab a large section of the
canvas and move it would speed things up considerably as well as be
useful for other things.

Elan

On Wed, Apr 22, 2009 at 1:10 PM, Ryan May <rm...@gm...> wrote:
> On Wed, Apr 22, 2009 at 10:11 AM, Elan Pavlov <ep...@gm...> wrote:
>>
>> I'm trying to use matplotlib for animating data as it is received from
>> an online source (online in the algorithmic
>> sense not internet:). I'd like the graph plot to be updated with high
>> frequency since the data changes rapidly. I've
>> used the BufferRegion with copy_from_bbox / restore_region and it
>> speeds up the plotting considerably but alas it's
>> still not good enough (with a large number of graphs and a large
>> number of data points in each graph).
>>
>> What I'd like to do is to utilize the fact that the animation is
>> updated in a predictable fashion (i.e., scrolling off
>> the screen to the left as new data arrives) in order to speed up the
>> animation. The idea would be to copy the right 99%
>> of the graph (or some other fraction) via some kind of function
>> similar to copy_from_bbox, move it 1% to the left and
>> then plot the new 1% of the data. The problem is that as far as I can
>> tell the copy_from_bbox/restore_region does not
>> actually allow changing the area in which it is restored. I've mucked
>> around in the source files a bit but to no avail.
>>
>> My question is then:
>> 1. Is there some other way to copy everything enclosed in a Bbox? or
>> 2. Is there some way to modify the region in which data reappears when
>> using restore_region?
>> 3. Perhaps I'm missing something?
>>
>> It would also be nice if it was possible to transform the plot (i.e.
>> make it larger/smaller depending on how the y-axis changes) although I
>> suppose this is doable via using an auxiliary canvas.
>>
>> I'm sure someone else has done this since it seems pretty natural and
>> useful for a variety of applications.
>
> Without a small example, it's hard to know for sure.  Are you using
> Line2D.set_data to update with new data or are you doing a new plot?  Since
> you have multiple graphs, have you looked at making a LineCollection object
> by hand, which will decrease the number of function calls when drawing?
>
> Just some ideas,
>
> Ryan
>
> --
> Ryan May
> Graduate Research Assistant
> School of Meteorology
> University of Oklahoma
> Sent from Norman, Oklahoma, United States



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