[Matplotlib-users] dynamic update in TkAgg ? (more)

[Gary P. <pa...@in...>]

> I've been trying to figure out how to do an dynamic update in TkAgg
without
> success.  Anyone have any pointers?
> I'm trying to recreate the functionality of the Pmw.Blt stripchart.
>
> -gary
>

I guess I should be a little more specific.    The part I'm having trouble
with is the dynamic update.  As a step along the way, I've got a gui with a
button that just replots some data slightly altered from the original.

If I use FigureCanvasTkAgg.show (schematically speaking) it will replot, but
just once. That is, my button's callback routine contains a loop that tries
to change the data (via set_ydata followed by ....show()) several times in a
row.  If I click the button, the data updates, but only once.  I click it
again, it the data updates once.  I remove the loop, the data updates once.
This strikes me as odd.  How should the graphics window know or care if I'm
in a python loop or not?

I'm thinking that a well-placed  call to
canvas.get_tk_widget.update_idletasks()  should do the job, but that hasn't
worked for me either.

Aside:  having played with anim.py I'm concerned about speed.  It seems that
the speed of anim.py is limited by my system, not by the call to
gtk.timeout_add().  I might be back asking about a solution that runs faster
... perhaps a lower level solution.  (Pmw.Blt works fast enough.)  Hmm... I
just tried anim.py again, and it won't run.  I've just upgraded to 0.54.
Odd ... it opens a Tk window.  I'll try that again later after I reboot.
I'm on WinXP.

Comment:  I don't have a handle at all on how the graphics system is
organized.  For example, what is a figure manager?  When do I use it?  I
don't seem to need it, but there it is, and some of the examples use it.
Looking through the docstrings I find myself going in circles.  Maybe I'm
digging too deeply for my own good.  Maybe you developer types might add to
your to-do list a description of the stucture of the graphics system.

thanks again,
gary

btw, for every task other than animation, matplotlib is the bomb.  great
job.