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From: josef@nixdorf.de (Moellers)
Newsgroups: comp.graphics
Subject: Info on L-systems wanted
Summary: How do I interpret L-systems generated strings?
Keywords: L-systems fractals
Message-ID: <josef.657790969@peun11>
Date: 5 Nov 90 07:42:49 GMT
Sender: news@nixpbe.nixdorf.de
Lines: 24


Hi,
In "Circuit Cellar INK" there was an article on Fractals which referred
to L-systems (L stands for Lindenmayer).
In this system, (veeeery) long character strings are generated using a
so-called "axiom" (e.g. "G") and one or more production rules (e.g.
"G" -> "GFX(+G)(-G)" -and- "X" -> "X(-FFF)(+FFF)FX").
If You apply these rules one or more times, and interpret the generated
string properly, You can generated quite natural looking plants.

My question is on the "properly".
The article says:
	"Here, F represents a graphically drawn line and each + or - is
	used to specify a change in the orientation for the drawing of
	the next line segment"
But ... how do I interpret the "G"s and "X"s? Or are they just
"nonterminals" that must be ignored when interpreting the result?
What about the parentheses?

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