Blank equation when exported to HTML using dvipng

Blank equation when exported to HTML using dvipng

[Richard Stanton]

Here's a very simple ORG file:

--------

#+OPTIONS: LaTeX:dvipng

* Test file
\begin{equation}
x=\sqrt{b}
\end{equation}   

----------

When I export this to HTML (Org-mode version 7.8.11 (release_7.8.11-12-gc55405 @ c:/emacs/site-lisp/org-mode/lisp/)), the equation comes out blank. 

The HTML file contains the following code:

<img src="ltxpng/test_660c6efb146974e9d77e2de45f258385867ef389.png" alt="\begin{equation}
x=\sqrt{b}
\end{equation}"/>

However, directory ltxpng is empty.

I'm running Emacs 24.0.97 under Windows Vista with MikTeX 2.09 installed and PATH set so that I can call pdflatex, dvipng, etc. from the command line just fine.

Any thoughts about what might be going wrong? 

Re: Blank equation when exported to HTML using dvipng

[Richard Stanton]

> From: Puneeth Chaganti [mailto:punchagan@gmail.com]
> Sent: Sunday, May 27, 2012 10:48 PM
> To: Richard Stanton
> Subject: Re: [O] Blank equation when exported to HTML using dvipng
> 
> On Mon, May 28, 2012 at 11:13 AM, Richard Stanton
> <stanton@haas.berkeley.edu> wrote:
> > Here's a very simple ORG file:
> >
> > --------
> >
> > #+OPTIONS: LaTeX:dvipng
> >
> > * Test file
> > \begin{equation}
> > x=\sqrt{b}
> > \end{equation}
> >
> > ----------
> >
> > When I export this to HTML (Org-mode version 7.8.11 (release_7.8.11-12-
> gc55405 @ c:/emacs/site-lisp/org-mode/lisp/)), the equation comes out
> blank.
> >
> > The HTML file contains the following code:
> >
> > <img src="ltxpng/test_660c6efb146974e9d77e2de45f258385867ef389.png"
> > alt="\begin{equation} x=\sqrt{b} \end{equation}"/>
> >
> > However, directory ltxpng is empty.
> >
> > I'm running Emacs 24.0.97 under Windows Vista with MikTeX 2.09 installed
> and PATH set so that I can call pdflatex, dvipng, etc. from the command line
> just fine.
> >
> > Any thoughts about what might be going wrong?
> 
> Do you get any error messages?  Do you have dvipng installed?
> 
> --
> Puneeth

The *Messages* buffer shows the following:

Exporting...
Loading reftex...done
Creating LaTeX image 1
Failed to create dvi file from c:/Users/stanton/AppData/Local/Temp/orgtex5660EuC.tex
Exporting...
image ltxpng/test_660c6efb146974e9d77e2de45f258385867ef389.png t
Saving file c:/projects/texintro/web/test.html...
Wrote c:/projects/texintro/web/test.html
HTML export done, pushed to kill ring and clipboard

Investigating further, the log file associated with the tex file listed above shows the following:

Package ifplatform Warning: 
    shell escape is disabled, so I can only detect \ifwindows.

)
\minted@bgbox=\box31
\minted@code=\write4
\@float@every@listing=\toks22
\c@listing=\count106
)

! Package minted Error: You must invoke LaTeX with the -shell-escape flag.

See the minted package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
                                                  
l.7 \usepackage
               [latin1]{inputenc}
? 
! Emergency stop.
 ...                                              
                                                  
l.7 \usepackage
               [latin1]{inputenc}
Pass the -shell-escape flag to LaTeX. Refer to the minted.sty documentation for
 more information.

So now I can see what the problem is, but how do I tell org-mode to call latex with the -shell-escape flag?

Re: Blank equation when exported to HTML using dvipng

[Nick Dokos]

Richard Stanton <stanton@haas.berkeley.edu> wrote:

> ...
> 
> So now I can see what the problem is, but how do I tell org-mode to
> call latex with the -shell-escape flag?
> 

You can customize org-latex-to-pdf-process (or
org-e-latex-pdf-process[fn:1] if you are using the new exporter). In my
case, I have

,----
| org-latex-to-pdf-process is a variable defined in `org-latex.el'.
| Its value is ("texi2dvi --pdf %f")
| Original value was 
| ("pdflatex -interaction nonstopmode -output-directory %o %f" "pdflatex -interaction nonstopmode -output-directory %o %f" "pdflatex -interaction nonstopmode -output-directory %o %f")
`----

but texi2dvi probably does not exist on windows (and you still have to
patch it even on linux). Just add --shell-escape after every pdflatex
(or whatever command is invoked on windows).

Nick

Footnotes:

[fn:1] NB: different spelling in the two cases - not only the added "e-" but
       also the missing "-to".

Re: Blank equation when exported to HTML using dvipng

[Richard Stanton]

In my init.el, I have

(setq org-latex-to-pdf-process 
      '("pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"
        "pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"
        "pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"
        "pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"))

The problem is that when I export to HTML with the dvipng option, it's calling latex, not pdflatex, so I don't think this option has an effect.

> -----Original Message-----
> From: nicholas.dokos@hp.com [mailto:nicholas.dokos@hp.com]
> Sent: Monday, May 28, 2012 7:08 AM
> To: Richard Stanton
> Cc: Puneeth Chaganti; emacs-orgmode@gnu.org
> Subject: Re: [O] Blank equation when exported to HTML using dvipng
> 
> Richard Stanton <stanton@haas.berkeley.edu> wrote:
> 
> > ...
> >
> > So now I can see what the problem is, but how do I tell org-mode to
> > call latex with the -shell-escape flag?
> >
> 
> You can customize org-latex-to-pdf-process (or org-e-latex-pdf-
> process[fn:1] if you are using the new exporter). In my case, I have
> 
> ,----
> | org-latex-to-pdf-process is a variable defined in `org-latex.el'.
> | Its value is ("texi2dvi --pdf %f")
> | Original value was
> | ("pdflatex -interaction nonstopmode -output-directory %o %f" "pdflatex
> | -interaction nonstopmode -output-directory %o %f" "pdflatex
> | -interaction nonstopmode -output-directory %o %f")
> `----
> 
> but texi2dvi probably does not exist on windows (and you still have to patch
> it even on linux). Just add --shell-escape after every pdflatex (or whatever
> command is invoked on windows).
> 
> Nick
> 
> Footnotes:
> 
> [fn:1] NB: different spelling in the two cases - not only the added "e-" but
>        also the missing "-to".

Re: Blank equation when exported to HTML using dvipng

[Nick Dokos]

Richard Stanton <stanton@haas.berkeley.edu> wrote:

> In my init.el, I have
> 
> (setq org-latex-to-pdf-process 
>       '("pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"
>         "pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"
>         "pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"
>         "pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"))
> 
> The problem is that when I export to HTML with the dvipng option, it's calling latex, not pdflatex, so I don't think this option has an effect.
> 

Ah, right: that's hardwired and needs source code changes.  The call is
in org.el:org-create-formula-image-with-dvipng. This was reported by
Ista Zahn (see http://thread.gmane.org/gmane.emacs.orgmode/50533). I
would encourage you to submit a patch for this[fn:1] - maybe make it
conditional on the value of org-export-latex-listings.

Nick

Footnotes:

[fn:1] Unfortunately I cannot.