The manual says math environment need not be in \[ \].
\[
\begin{matrix}
1&d\\
d&d\\
\end{matrix}
\]
When I put mouse point on `begin' , I can get preview image through C-c C-x C-l.
When I put mouse point on `matrix' , I get two identical matrix with a square between them.
When I put mouse point on `1&d' , I get a square and \[ at above \] at below .

Thanks



2009/8/11 Carsten Dominik <carsten.dominik@gmail.com>

On Aug 11, 2009, at 3:41 PM, Nick Dokos wrote:

waterloo <waterloo2005@gmail.com> wrote:

Excuse me .
I put the following latex code in an org file , and put point in it ,C-c
C-x  C-l.  It don't produce the correct image. There is only an square
appearing . The latex environment is include in amsmath package, which is
include in Org Format Latex Header defautly.


\begin{matrix}
1&d\\
d&d\\
\end{matrix}


I cannot be sure whether "waterloo" sees the same problem (from his
description, it seems that he gets just an empty square which indicates
additional/different problems - maybe missing the dvipng program?),

Yes, this seems to be a different problem.  Maybe the problem is thatthe matrix environment must be inside a math environment?



but
I do see a problem.  Here is the org file:

,----
| #+LaTeX_HEADER: \usepackage{amsmath}

This is actually not necessary, I was mistaken here.


|
| * foo
|
| \[
| \begin{matrix}
| 1&d\\
| d&d\\
| \end{matrix}
| \]
|
`----

I can export this to LaTeX just fine (and I need the additional header,
at least in that case - I have not tried without it). But when I try the
preview C-c C-x C-l on the fragment, I get the preview of the matrix
twice with an empty square separating the two instances.  I attach a PNG
image of the result. I checked the image that is produced in the ltxpng
subdirectory: it's just the image of the matrix, no problem there.

Hmm, another fun and interesting bug!

Fixed now.  Thanks.

- Carsten