\documentclass{article}
\usepackage{com.braju.graphicalmodels}
\usepackage{amsmath}
% \special{papersize=40mm,80mm}
% \setlength{\pdfpagewidth}{40mm}
% \setlength{\pdfpageheight}{80mm}
% \usepackage[vcentering,dvips]{geometry}
% \geometry{papersize={80mm,120mm},total={80mm,120mm},margin=0mm}



\catcode`\@=11%

\pagestyle{empty}

\begin{document}
\TeXtoEPS

\LARGE
\psset{unit=10mm,arrowscale=1.5,linewidth=1.5pt}

\begin{pspicture}(0,0)(8,8)
  \SpecialCoor

  \rput(1,1){\GM@node[observed=true]{x_1}}
  \GM@label[angle=-180]{x_1}{$\boldsymbol{x}_1$}

  \rput(4,1){\GM@node[observed=true]{x_2}}
  \GM@label[angle=-180]{x_2}{$\boldsymbol{x}_2$}

  \rput(7,1){\GM@node[observed=true]{x_star}}
  \GM@label[angle=-180]{x_star}{$\boldsymbol{x}_{\star}$}

  \rput(1,3){\GM@node{f_1}}
  \GM@label[angle=140]{f_1}{$\boldsymbol{f}_1$}

  \rput(4,3){\GM@node{f_2}}
  \GM@label[angle=140]{f_2}{$\boldsymbol{f}_2$}

  \rput(7,3){\GM@node{f_star}}
  \GM@label[angle=140]{f_star}{$\boldsymbol{f}_{\star}$}


  \rput(1,5){\GM@node[observed=true]{y_1}}
  \GM@label[angle=-180]{y_1}{$\boldsymbol{y}_1$}

  \rput(4,5){\GM@node[observed=true]{y_2}}
  \GM@label[angle=-180]{y_2}{$\boldsymbol{y}_2$}

  \rput(7,5){\GM@node{y_star}}
  \GM@label[angle=-180]{y_star}{$\boldsymbol{y}_{\star}$}


  \ncline[arrows=->]{x_1}{f_1}
  \ncline[arrows=->]{f_1}{y_1}
  \ncline[arrows=->]{x_2}{f_2}
  \ncline[arrows=->]{f_2}{y_2}
  \ncline[arrows=->]{x_star}{f_star}
  \ncline[arrows=->]{f_star}{y_star}
  \ncline{f_1}{f_2}
  \ncline{f_2}{f_star}
  \nccurve[angleA=-25,angleB=-155]{f_1}{f_star}

\end{pspicture}

\endTeXtoEPS
\end{document}