\newdimen\unitlength 
\unitlength=1cm

\def\plot(#1,#2){%
  \rlap{\kern#1\unitlength\raise#2\unitlength%
        \hbox{$\scriptstyle\bullet\;(#1,#2)$}}}

\centerline{%
  \hbox{\plot(0,0)
        \plot(1,1)
        \plot(-3,2)}%
}