#!/usr/local/bin/perl
# peterson - generates a TeXdraw commands for the Peterson graph
#
# $Id: peterson,v 1.3 1994/01/28 23:46:57 pliam Exp $

require 'graphtex.pl';

#
# set up %posit array for objects in1..in5, out1..out5
#
$inrad = 7;   # radius of inner pentagon
$outrad = 15; # radius of outer pentagon
$theta = $pi/2;
foreach $i (1..5) {
   $x = $inrad*cos($theta);
   $y = $inrad*sin($theta);
   $posit{"in$i"} = "$x $y";
   $x = $outrad*cos($theta);
   $y = $outrad*sin($theta);
   $posit{"out$i"} = "$x $y";
   $theta += 2*$pi/5;
}

#
# set up connectivity array %connect
#
%connect = (
   'in1', '\ver \edg<in3>',
   'in2', '\ver \edg<in4>',
   'in3', '\ver \edg<in5>',
   'in4', '\ver \edg<in1>',
   'in5', '\ver \edg<in2>',
   'out1', '\ver \edg<out2> \edg<in1>',
   'out2', '\ver \edg<out3> \edg<in2>',
   'out3', '\ver \edg<out4> \edg<in3>',
   'out4', '\ver \edg<out5> \edg<in4>',
   'out5', '\ver \edg<out1> \edg<in5>'
);

#
# parse away, printing to standard out
#
open(OUT, ">&STDOUT");
&parse;
