E-Toys and Morphic for simple point plotting exercise?

I'd like to challenge some students (9 years old to 14 years old) to  
use Squeak to draw a Sierpenski Gasket (http://en.wikipedia.org/wiki/ 
Serpinski_gasket) as an experiment with random numbers.  To draw  
something like you see at (http://commons.wikimedia.org/wiki/ 
Sierpinski_triangle), one method is to pick a starting point,  
randomly select one of the three fixed corners, plot a line half way  
there and repeat from each new position.  I can seem to accomplish  
this awkwardly using E-Toys as follows:

- draw a sketch morph using paint tool or however you wish to obtain  
something that is visibly positioned at different points below
- add 2 number variables for each point to be used, i.e, point1X,  
point1Y, Point2X, Point2Y, Point3X, Point3Y
- add a script with random number tile generating 1, 2 or 3 that loops:
        - determine which of 3 fixed points is to be used this time
        - turn pen off
        - move half way to new fixed plot point
        - turn pen on
        - move one pixel to draw dot
        - turn pen off
        - move back one pixel and repeat above from current point

This works but it feels very clunky using E-Toys.  Screen shots here  
if there's interest:
http://dang.ath.cx/media/Squeak/plotting01/drawing01.jpg
http://dang.ath.cx/media/Squeak/plotting01/drawRandomly01.jpg

   Things I'd like to improve:

- a shorter E-Toys version
- a morphic version other than just 'view source' of E-Toys tiles  
version
- be able to subroutine or parameter-ize an E-Toys script with a  
point or two numbers instead just one parameter and/or repeating code
- find a suitable PlotMorph or other class which can be used for the  
E-Toys version rather than just scribble with penDown=true or create  
millions of 1 pixel LineMorphs
- most of the documentation for morphs with a "point: color" method  
indicate it is obsolete -- what is one to use plot a point if  
different than a one pixel line?

   Any input, thoughts or suggestions for improvement appreciated!

   Thanks.

   Best regards,

-- DanG
Daniel Green, Sun Microsystems
[hidden email], 877-481-0917
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On Nov 14, 2006, at 15:54 , Daniel Green wrote:

> I'd like to challenge some students (9 years old to 14 years old)  
> to use Squeak to draw a Sierpenski Gasket (http://en.wikipedia.org/ 
> wiki/Serpinski_gasket) as an experiment with random numbers.

I'm pretty sure Markus Gaelli did that once, surely he will chime in ...

>   Things I'd like to improve:
>
> - a shorter E-Toys version

See attached PNG for my version - four lines of tiles ;-)

> - a morphic version other than just 'view source' of E-Toys tiles  
> version

Hmm, there is a directly drawn version at

        http://minnow.cc.gatech.edu/squeak/1677

> - be able to subroutine or parameter-ize an E-Toys script with a  
> point or two numbers instead just one parameter and/or repeating code

Not in this version of etoys.

> - find a suitable PlotMorph or other class which can be used for  
> the E-Toys version rather than just scribble with penDown=true or  
> create millions of 1 pixel LineMorphs

If you make your pen object small, just use the "stamp" tile.

- Bert -




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