%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 5-6-7 on page 234.
%% 
%%  Copyright (C) 2007 Michel Goossens, Frank Mittelbach, Denis Roegel, Sebastian Rahtz, Herbert Vo\ss 
%% 
%%  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.
%% 

\documentclass{ttctexa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{183.83385pt}
\setlength\parindent{0pt}
\StartShownPreambleCommands
\usepackage{pstricks}
\StopShownPreambleCommands
\begin{document}
\psset{linewidth=3mm,unit=0.6}
\begin{pspicture}[showgrid=true](3,2)
  \psline(0,0)(1,2)(2,0)(3,2)
\end{pspicture}\\[3ex]
\begin{pspicture}[showgrid=true](4,2)
  \pstVerb{ 1 setlinejoin }
  \psline(0,0)(1,2)(2,0)(3,2)(4,0)
\end{pspicture}\\[3ex]
\begin{pspicture}[showgrid=true](3,2)
  \pscustom{\code{2 setlinejoin}
            \psline(0,0)(1,2)(2,0)(3,2)}
\end{pspicture}

\end{document}