Seeking compelling high school examples

[Christopher Sawtell]

On Sun, 27 Apr 2003 14:25, Kim Rose wrote:
> --
> Greetings -
>
> Viewpoints Research is working on updating the Squeakland.org
> website.  As part of this project,  we wish to point to a variety of
> schools, groups, community centers, etc. using Squeak (the Etoy-tile
> scripting component) and include interesting project examples.

I have added a graphical angle watcher to Randy Caton's Pendulum.
It draws a sinusoidal graph in real time of the simulated pendulum's angle as 
it swings to and fro. I have also put some annotations on it. The plotter 
script is not synchronous with the pendulum script, so by changing the sample 
rate of the plotter one can demonstrate the effect of too slow a rate 
destroys the effective measurement of the waveform. It's quite pretty, though 
I say so myself, and my 13 year old son was somewhat impressed.

It's here:-

http://berty.dyndns.org/CSpendulum.pr

While doing this I noticed that there's a minor bug in the drawing of the 
graph lines on a Playfield. The horizontal lines appear to be drawn relative 
to the top of the Playfield, whereas the 'y' coordinate of an object is 
measured with respect to the bottom of the Playfield. This means that unless 
the height of the Playfield is an exact multiple of the graticule size then 
the actual 'y' co-ordinate and its values as read off the graph do not 
correspond. This is demonstrated with a simple project here:-

http://berty.dyndns.org/GraphBug.pr

The red plotted line should go through the corners of the green squares 
precisely.

HTH

--
C. S.