%% 
%%  A DANTE-Edition example
%% 
%%  Example 15-01-53 on page 185.
%% 
%%  Copyright (C) 2011 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[]{article}
\pagestyle{empty}
\setlength\textwidth{201.70511pt}
\setlength\parindent{0pt}

\usepackage{pst-plot}
\def\data{0 0 1 4 1.5 1.75 2.25 4 2.75 7 3 9} \psset{lly=-0.5cm}

\begin{document}
\begin{psgraph}[axesstyle=none,ticks=none,labels=none](0,0)(3.0,9.0){12cm}{5cm}
\pscustom[fillstyle=solid,fillcolor=red!30,linestyle=none]{%
  \listplot{\data}\psline(3,9)(3,0)}
\pscustom[fillstyle=solid,fillcolor=blue!20,linestyle=none]{%
  \listplot{\data}\psline(3,9)(0,9)}
\listplot[linewidth=2pt]{\data}
\psaxes[axesstyle=frame,ticksize=0 5pt,xsubticks=20,ysubticks=4,
    tickstyle=inner,dy=2,Dy=2,tickwidth=1.5pt,subtickcolor=black](0,0)(3,9)
\rput*(2.5,3){level 1}\rput*(1,7){level 2}
\end{psgraph}
\end{document}