Thanks very much.  asymptote's function is very much like tikz . I can use
asymptote.
Besides asymptote, I can use metapost.

2009/8/17 Eric Schulte <schulte.eric@gmail.com>

> Sorry,
>
> Please disregard this email, I didn't realize tikz/pgf was a package of
> TeX macros and not an external tool. -- Eric
>
> "Eric Schulte" <schulte.eric@gmail.com> writes:
>
> > Hi,
> >
> > Adding support for a new block type is fairly easy for any tool that can
> > be called from the command line.  If you would like to try this please
> > read the documentation of org-exp-blocks on worg [1] and follow the
> > example of the asymptote block type [2].
> >
> > Best -- Eric
> >
> > Footnotes:
> > [1]  http://orgmode.org/worg/org-contrib/org-exp-blocks.php
> >
> > [2]  http://orgmode.org/worg/org-contrib/org-exp-blocks.php#sec-4.1
>