%% 
%%  A DANTE-Edition example
%% 
%%  Example 27-02-7 on page 513.
%% 
%%  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{177.70511pt}
\setlength\parindent{0pt}
\usepackage{filecontents}
\begin{filecontents*}{data2T.csv}
1, 0.5, 2, 0.5
1, 2, 1.5, 1
\end{filecontents*}

\usepackage{pstricks,pst-bar}

\begin{document}
\readpsbardata[header=false]{\data}{data2T.csv}
\begin{pspicture}(-0.5,-0.1)(4,2)
  \psbarchart[barsep=0.05,barstyle={red,green},
    chartstyle=cluster]{\data}
\end{pspicture}

\begin{pspicture}(-0.5,-0.1)(4,2)
  \psbarchart[barsep=0.2,barstyle={red,green},
    chartstyle=cluster]{\data}
\end{pspicture}
\end{document}