[Xy-pic] Difference between dvi and pdf output

[Michael Barr]

Can anyone explain the difference in ouput between this file:

\documentclass{article}
\pdfoutput1
\usepackage{xy}

\begin{document}

\begin{xy}
0;<1cm,0cm>:
(8,3) *\cir<2cm>{},
(8.3,2.7) *\cir<1.4cm>{},
(6.4,3.1) *\cir<0.2cm>{}
\end{xy}

\end{document}

and this one:


\documentclass{article}
\pdfoutput0
\usepackage{xy}

\begin{document}

\begin{xy}
0;<1cm,0cm>:
(8,3) *\cir<2cm>{},
(8.3,2.7) *\cir<1.4cm>{},
(6.4,3.1) *\cir<0.2cm>{}
\end{xy}

\end{document}

They differ only in the output chosen.  The first gives pdf and the
second dvi.

Incidentally, the second output is duplicated if the \usepackage{xy}
precedes the line \pdfoutput1, which I find doubly bizarre.


Michael Barr


-- 
The modern conservative is engaged in one of man's oldest exercises in
moral philosophy--the search for a superior moral justification
for selfishness.  --J.K. Galbraith