%%
%% Ein Beispiel der DANTE-Edition
%%
%% 1. Auflage
%%
%%
%% Copyright (C) 2013 Herbert Voss
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3
%% of this license or (at your option) any later version.
%%
%% See
http://www.latex-project.org/lppl.txt for details.
%%
%%
%% ====
% Show page(s) 1
%%
%%
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{352.81416pt}
%StartShownPreambleCommands
\usepackage{luamplib} \newsavebox\MPBox
%StopShownPreambleCommands
\begin{document}
\begin{lrbox}{\MPBox}
\begin{mplibcode}
vardef randomwalk(expr C,wd,ht,n,l,f,r)=save A,B,a,b;
pair A,B;a=0;
draw ((wd,-ht)--(wd,ht)--(-wd,ht)--(-wd,-ht)--cycle) shifted C;
A=C;
for i=1 upto n:
forever:
b:=a*f+((uniformdeviate 2)-1)*180r;
B:=A+l*(uniformdeviate 1)*dir(b);
if (abs(xpart(B-C))>= wd) or (abs(ypart(B-C))>= ht):
B:=A+l*(uniformdeviate 2)*dir(b+180);
fi;
exitif (abs(xpart(B-C))< wd) and (abs(ypart(B-C))< ht);
endfor;
draw A--B;A:=B;a:=b mod 360;
endfor;
enddef;
beginfig(1)
randomwalk(origin, 2cm,2cm,1000,10mm,0,1);
randomwalk((5cm,0),2cm,2cm,3000, 4mm,1,0.3);
endfig;
\end{mplibcode}
\end{lrbox}
Text \fbox{\usebox\MPBox} Text
\end{document}
