Re: [Visualpython-users] slider

[Andrew D. <dou...@la...>]

On Tue, 27 Jan 2004, P H Borcherds wrote:

> Dear all
>
> I have downloaded and run Andy Dougherty's program. It is helpful to have an
> example like this to see how to put several windows on the screen

Thanks.  I don't pretend it's "good" or "right" -- it's just the first
thing that worked for me :-).

> I have increased the number of points displayed in the poincare section to
> 400 (see attached jpeg: 40 points is not sufficient).

That, of course, depends both on what you're trying to do and on the speed
of your computer (and/or the patience of your users!).  In my case, the
students were supposed to be exploring period-doubling, so 40 points was
plenty.  Obviously for more interesting behavior, more would usually be
better.

> On my computer (PC with tft screen) the DISPLAY of the pendulum is very
> jerky: Can anyone offer help on this?

Only the observation that I see such behavior (or much worse, a failure to
even run) on slower machines or on machines with strained resources.  It
won't work at all on any of my Linux systems (though none of them are
blazingly fast) nor on some of the slower windows systems around here.

This is a general problem I've observed with many programs using gdots.
I tend not to see it so much using gcurve.  I also tend to see such
problems when using more than one window, especially on my Linux systems.
I vaguely suspect that there is a buried race condition somewhere in the
inter-thread communications, and also that there's something amiss with
the gdots() representation.  However, I haven't been able to track it down
further.  I may have some oppotunities this spring since I'm using vpython
in a course.

-- 
    Andy Dougherty		dou...@la...