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

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

Thanks,
Nick