[pstricks] Moving Image Origin on Page

[Rich Shepard]

   It's been a long time since I needed to generate figures for a report so
I've been re-reading Herbert's PSTricks book to re-learn what to do.

   Unfortunately, I'm stuck at the very earliest stage: setting the figure
size and having it centered on the page. I've tried using the origin
command, but I'm not putting it in the proper place, properly specifying
settings, or both.

   Here's the stub for the eventual figure:

\documentclass[letterpaper,10pt]{article}
\usepackage{pstricks-add}

\begin{document}
   \begin{pspicture}(-1.5in,-0.5in)(6in,4in)
     \psgrid[subgriddiv=1in,gridcolor=black!25]
     \psline[linewidth=2pt](1.25in,1.25in)(3.5in,1.25in)
   \end{pspicture}
\end{document}

   The \psgrid is temporary for properly aligning and sizing the figure. When
that's correct I'll adjust the line size and placement and add the other
elements needed.

   A clue to what I've not done correctly will be much appreciated.

Rich