%% 
%%  A DANTE-Edition example
%% 
%%  Example 16-09-1 on page 263.
%% 
%%  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{375.57637pt}
\setlength\parindent{0pt}
\usepackage[utf8]{inputenc}
\def\Lcs#1{\texttt{\textbackslash#1}}

\usepackage{pst-node}

\begin{document}
Especially when defining nodes such as \Lcs{cnode}\{3pt\}\{A\}, \cnode*{3pt}{A}
the coordinates aren't known explicitly as the nodes appear in the middle of text or
are the result of a temporary calculation, but sometimes you do want to know those
coordinates. This isn't possible at \TeX{} level as explained before, so we have to
fall back on the possibilities that PSTricks offers.

\bigskip
\begin{pspicture}[showgrid](1,1)
  \Cnode*[radius=0.1](0.5,0.5){B}
  \makeatletter
  \psline[arrowscale=2,linestyle=dashed]{->}(B)(!%
    tx@NodeDict begin
      /N@B load GetCenter /yB ED /xB ED % centre of node B
      /N@A load GetCenter /yA ED /xA ED % centre of node A
      xA xB sub 0.7 mul xB add \pst@number\psxunit div
      yA yB sub 0.7 mul yB add \pst@number\psyunit div
    end)
  \makeatother
\end{pspicture}
\end{document}
