# Direc­tory graphics/pstricks/contrib/vaucanson-g

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%% Package VauCanSon-G'  version 0.4
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%% IMPORTANT NOTICE:
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%% Copyright (C) 2002-2008 Sylvain Lombardy and Jacques Sakarovitch
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%% This package may be distributed under the terms of the LaTeX Project
%% Public License, as described in lppl.txt in the base LaTeX distribution.
%% Either version 1.0 or, at your option, any later version.
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Vaucanson-G : A LaTeX package for drawing automata and graphs

Vaucanson-G is based on PSTricks and PSTricks does not generate dvi instructions but instead
directly generate postscript commands. As a result, the drawings composed by Vaucanson-G
are not correctly visible under a dvi previewer. A very common outcome is an unscaled drawing and
all the labels are written at the origin.

Vaucanson-G is a package of macros that allow to draw automata and graphs within
texts written using LaTeX.
Nota Bene: The commands for graphs are still under construction
and are not described yet neither below nor in the manual.

The design of Vaucanson-G implements the following
underlying philosophy: "simple" automata should be
described with simple commands.
The complexity of commands (or the number of things to be remembered
to use them) should gradually grow with the complexity of the figure
composed by these commands.

The following example shows how a simple automaton can be drawn
with commands, in which only the minimal information needed (position
and label of states, shape and label of transitions) is made explicit.

\begin{VCPicture}{(0,-2)(6,2)}
% states
\State[p]{(0,0)}{A} \State{(3,0)}{B} \State[r]{(6,0)}{C}
% initial--final
\Initial{A} \Final{C}
% transitions
\EdgeL{A}{B}{a} \ArcL{B}{C}{b} \ArcL{C}{B}{b}
\LoopN{A}{a} \LoopS{C}{d}
%
\end{VCPicture}

This is achieved by the implicit definition of a large number of
parameters that control the geometry of the figure: size of states,
width of lines,...
The way these parameters can be handled and modified yields what is
the second feature of Vaucanson-G:
-- the easy definition of styles for the elements of figures.
-- the capability of handling the figures both in size and
appearance without modifying them.

Vaucanson-G is a set of macros that uses commands of the PSTricks package,
due to Timothy van Zandt and that appears in the current version
of the LaTeX distribution.
The knowledge of this beautiful macro package is not necessary to use
the Vaucanson-G commands.

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