LINDENMAYER SYSTEMS

WRITTEN BY: Donald Kiel, Department of Math and Computer Science, Cal 
State, Los Angeles (dkiel@neptune.calstatea.edu)

CATEGORY: Fractals

APPLICATION:
 
Lindenmayer systems allow the definition of natural looking objects(sometimes 
called "graftals") to be described in formal language.  For example, one simple 
"axiom" and one relatively short production rule can be used to generate  a bush.  
For example, the default Axiom is F, the rule is F[+F]F[-F]F, and the angle is Pi/7.  
At the first level every F is replaced by the rule F[+F]F[-F]F. This would be drawn 
as one step forward(the first F, the size of which depends on the scale),  then a 
branch drawn one step forward at an angle of Pi/7)(the [+F] ), then back to the 
trunk and one step forward, then a branch to the left ( the [-F] ), and finally one 
step forward again.  To get the second level, each F in the  derived formula is 
replaced by rule and the resulting formula is drawn.  

The user can construct new rules or can elect one of  the choices in the 
Examples menu.  The choices include other bushes, the Koch snowflake,  and 
the Koch island.  

USES:  Graphics and automata classes.

DEVELOPMENT :NeXTSTEP 2.0