\documentclass{article}
\usepackage{com.braju.graphicalmodels}

\catcode`\@=11%

\pagestyle{empty}

\begin{document}
\TeXtoEPS

\LARGE
\psset{unit=10mm,arrowscale=1.5,linewidth=1.5pt}
\begin{pspicture}(-3,-3)(15,10)%\showgrid
  \SpecialCoor



   \rput(1,2){\GM@node[observed=true]{xi1}} \GM@label[angle=140]{xi1}{$x_{1}$}
   \rput(3,2){\GM@node[observed=true]{xi2}} \GM@label[angle=140]{xi2}{$x_{2}$}
   \rput(7.8,2){\GM@node[observed=true]{xiTi}}\GM@label[angle=140]{xiTi}{$x_{T}$}


   \rput(1,4){\GM@node[observed=false]{si1}}  \GM@label[angle=-135]{si1}{$z_{1}$}
   \rput(3,4){\GM@node[observed=false]{si2}}  \GM@label[angle=-135]{si2}{$z_{2}$}
   \rput(7.8,4){\GM@node[observed=false]{siTi}} \GM@label[angle=-135]{siTi}{$z_{T}$}


   \ncline[arrows=->]{si1}{xi1}
   \ncline[arrows=->]{si2}{xi2}
   \ncline[arrows=->]{siTi}{xiTi}
   
   \ncline[arrows=->]{si1}{si2}
   \ncline[arrows=->]{xi1}{xi2}

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   \psline[arrows=->](6.2,4)(7.5,4)

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   \psline[arrows=->](6.2,2)(7.5,2)


   \psdots*(4.9,2)(5.4,2)(5.9,2)
   \psdots*(4.9,4)(5.4,4)(5.9,4)

\end{pspicture}

\endTeXtoEPS
\end{document}