Turtle Graphics

[david bovill]

> Dave,
>
> I'm don't know what I-systems are.

http://en.wikipedia.org/wiki/L-system
http://www.cs.unh.edu/~charpov/Programming/L-systems/
http://www.fraktalwelt.de/lsys/einf_lsys.htm (German)

> But by trees I presume you means things like:
>
> on Tree L,dL
>   if L > 5 then
>     left 45
>     forward L
>     tree L/2
>     back L
>     right 90
>     forward L
>     tree L/2
>     back L
>     left 45
>   end if
> end Tree

The syntax I use for this would be of the form "+[F]--F" - where "F  
"is forward ("f" is forward without drawing), "+" is rotate left, "-"  
is rotate right and "[F]" is push with "]" as pop for creating branches.

The link to Turtle Graphics is in using the strings like "+[F]-- 
F" (for controlling the Turtle) and then passing them into an l- 
system - see http://www.biologie.uni-hamburg.de/b-online/e28_3/lsys.html

>
> I don't know what to suggest. Maybe put your examples in the  
> personal users' space in Rev OnLine?

Have to wait a week or two till I get my nice new license - I'm a  
Metacard developer :)