Dear list, I've been trying to write short scientific reports that I can export to both LaTeX and HTML. So far I've managed to figure out how to include equations, images, references, and how to include labels and cross reference between all these things. The only problem I have is that I can't get numbered equations in both LaTeX and HTML. Using the snippet below, I'm able to get a numbered equation in HTML but not in LaTeX. I've put loadFiles: ["extensions/eqn-number.js"], in jsMath/easy/load.js. If I replace the $$ by \begin{equation} and \end{equation}, I get a numbered equation in LaTeX but not in HTML. How can I get numbered equations in both HTML and LaTeX? Thanks, Sam ------- #+TITLE: A simple equation #+STYLE: <SCRIPT SRC="jsMath/easy/load.js"></SCRIPT> #+OPTIONS: LaTeX:verbatim * A simple equation This is to test writing equations with org-mode. Hopefully MathJax is going to be used. $$ \label{eq:1} x_{1,2} = \frac{-b \pm \sqrt{\Delta}}{2a} $$ Equation \ref{eq:1} gives the roots of a polynomial of order 2.

```
Samuel Sinayoko <s.sinayoko@soton.ac.uk> writes:
> Dear list,
>
> I've been trying to write short scientific reports that I can export to
> both LaTeX and HTML. So far I've managed to figure out how to include
> equations, images, references, and how to include labels and cross
> reference between all these things.
>
> The only problem I have is that I can't get numbered equations in both
> LaTeX and HTML. Using the snippet below, I'm able to get a numbered
> equation in HTML but not in LaTeX. I've put
> loadFiles: ["extensions/eqn-number.js"],
> in jsMath/easy/load.js. If I replace the $$ by
> \begin{equation} and \end{equation}, I get a numbered equation in LaTeX
> but not in HTML.
>
> How can I get numbered equations in both HTML and LaTeX?
I can't help you wish HTML unfortunately but I can summarise the issue
in LaTeX.
With the standard document class (article say), equations can be either
"displayed" or "inline". Only displayed equations are numbered and then
only if you use =equation= (or =align=, =eqnarray=, etc). $$ ... $$ is
equivalent to \[ ... \] which is essentially equivalent to the
unnumbered version of \begin{equation} (aka \begin{equation*}).
The trick would be to get the HTML exporter to apply the same processing
to \begin{equation} ... \end{equation} as it does to $$ ... $$, I guess?
--
: Eric S Fraga (GnuPG: 0xC89193D8FFFCF67D) in Emacs 24.0.50.1
: using Org-mode version 7.5 (release_7.5.399.g01eb)
```

```
Thanks Eric. I think you're right. It would make sense to use
\begin{equation} \end{equation} with HTML export to number equations.
I've put a minimal example below showing what is happening.
--
#+TITLE: Equation numbering
#+STYLE: <SCRIPT SRC="jsMath/easy/load.js"></SCRIPT>
* Numbered in HTML export / Not numbered in LaTeX
Equation is numbered and can be referenced in HTML export. Equation is
*not* numbered in LaTeX export.
$$
\label{eq:1}
y = ax + b
$$
Equation \ref{eq:1} is a polynomial of order 1.
* Not numbered in HTML / Numbered in LaTeX
Equation is not numbered but can be referenced in HTML export. Equation
is numbered in LaTeX export.
\begin{equation}
\label{eq:1}
y = ax + b
\end{equation}
Equation \ref{eq:1} is not numbered but can be referenced in HTML
export. It is numbered in LaTeX export.
--
I also think the right behaviour would be to have a numbered equation in
the second case in both HTML and LaTeX, and an unnumbered equation in
the first case in both HTML and LaTeX. Does everyone agree?
I'd be happy to try and change the behaviour of the HTML export if
someone can point me in the right direction.
Cheers,
Sam
On 16/06/11 08:53, Eric S Fraga wrote:
> Samuel Sinayoko <s.sinayoko@soton.ac.uk> writes:
>
>
>> Dear list,
>>
>> I've been trying to write short scientific reports that I can export to
>> both LaTeX and HTML. So far I've managed to figure out how to include
>> equations, images, references, and how to include labels and cross
>> reference between all these things.
>>
>> The only problem I have is that I can't get numbered equations in both
>> LaTeX and HTML. Using the snippet below, I'm able to get a numbered
>> equation in HTML but not in LaTeX. I've put
>> loadFiles: ["extensions/eqn-number.js"],
>> in jsMath/easy/load.js. If I replace the $$ by
>> \begin{equation} and \end{equation}, I get a numbered equation in LaTeX
>> but not in HTML.
>>
>> How can I get numbered equations in both HTML and LaTeX?
>>
> I can't help you wish HTML unfortunately but I can summarise the issue
> in LaTeX.
>
> With the standard document class (article say), equations can be either
> "displayed" or "inline". Only displayed equations are numbered and then
> only if you use =equation= (or =align=, =eqnarray=, etc). $$ ... $$ is
> equivalent to \[ ... \] which is essentially equivalent to the
> unnumbered version of \begin{equation} (aka \begin{equation*}).
>
> The trick would be to get the HTML exporter to apply the same processing
> to \begin{equation} ... \end{equation} as it does to $$ ... $$, I guess?
>
```

Thanks Eric. I think you're right. It would make sense to use \begin{equation} \end{equation} with HTML export to number equations. I've put a minimal example below showing what is happening. -- #+TITLE: Equation numbering #+STYLE: <SCRIPT SRC="jsMath/easy/load.js"></SCRIPT> * Numbered in HTML export / Not numbered in LaTeX Equation is numbered and can be referenced in HTML export. Equation is *not* numbered in LaTeX export. $$ \label{eq:1} y = ax + b $$ Equation \ref{eq:1} is a polynomial of order 1. * Not numbered in HTML / Numbered in LaTeX Equation is not numbered but can be referenced in HTML export. Equation is numbered in LaTeX export. \begin{equation} \label{eq:1} y = ax + b \end{equation} Equation \ref{eq:1} is not numbered but can be referenced in HTML export. It is numbered in LaTeX export. -- I also think the right behaviour would be to have a numbered equation in the second case in both HTML and LaTeX, and an unnumbered equation in the first case in both HTML and LaTeX. Does everyone agree? I'd be happy to try and change the behaviour of the HTML export if someone can point me in the right direction. Cheers, Sam

```
Using the org-special-blocks library org-mode will recognize blocks in the
form
: #+begin_something
: bla bla bla
: #+end_something
Then you could write
: #+begin_equation
: y=ax+b
: #+end_equation
in org-mode. It would be translated to
: \begin{equation}
: y=ax+b
: \end{equation}
in latex and
: <div class="equation">
: y=ax+b
: </div>
in html.
Can mathjax be configured to process anything inside <div class="equation">?
If not, maybe the #+begin_equation should be a built-in block in org-mode,
also with a fast template (maybe "<eq").
--
Darlan Cavalcante
At Thu, 16 Jun 2011 08:53:24 +0100,
Eric S Fraga <e.fraga@ucl.ac.uk> wrote:
>
> Samuel Sinayoko <s.sinayoko@soton.ac.uk> writes:
>
> > Dear list,
> >
> > I've been trying to write short scientific reports that I can export to
> > both LaTeX and HTML. So far I've managed to figure out how to include
> > equations, images, references, and how to include labels and cross
> > reference between all these things.
> >
> > The only problem I have is that I can't get numbered equations in both
> > LaTeX and HTML. Using the snippet below, I'm able to get a numbered
> > equation in HTML but not in LaTeX. I've put
> > loadFiles: ["extensions/eqn-number.js"],
> > in jsMath/easy/load.js. If I replace the $$ by
> > \begin{equation} and \end{equation}, I get a numbered equation in LaTeX
> > but not in HTML.
> >
> > How can I get numbered equations in both HTML and LaTeX?
>
> I can't help you wish HTML unfortunately but I can summarise the issue
> in LaTeX.
>
> With the standard document class (article say), equations can be either
> "displayed" or "inline". Only displayed equations are numbered and then
> only if you use =equation= (or =align=, =eqnarray=, etc). $$ ... $$ is
> equivalent to \[ ... \] which is essentially equivalent to the
> unnumbered version of \begin{equation} (aka \begin{equation*}).
>
> The trick would be to get the HTML exporter to apply the same processing
> to \begin{equation} ... \end{equation} as it does to $$ ... $$, I guess?
> --
> : Eric S Fraga (GnuPG: 0xC89193D8FFFCF67D) in Emacs 24.0.50.1
> : using Org-mode version 7.5 (release_7.5.399.g01eb)
>
```

```
Unfortunately this is not what jsMath expects. We get this in the html
file (see attached files for full source)
---
<p>This is what we want
$$
\label{eq:1}
y = ax + b
$$
</p>
<p>This is what we get
<div class="EQUATION">
\label{eq:1}
y = ax + b
</div>
</p>
--
What we need to do is to replace \begin{equation} ... \end{equation}
with $$ ... $$ in the HTML export. Any idea of how to do this?
Sam
On 16/06/11 15:37, Darlan Cavalcante Moreira wrote:
> Using the org-special-blocks library org-mode will recognize blocks in the
> form
> : #+begin_something
> : bla bla bla
> : #+end_something
>
> Then you could write
> : #+begin_equation
> : y=ax+b
> : #+end_equation
> in org-mode. It would be translated to
> : \begin{equation}
> : y=ax+b
> : \end{equation}
> in latex and
> : <div class="equation">
> : y=ax+b
> : </div>
> in html.
>
> Can mathjax be configured to process anything inside <div class="equation">?
>
> If not, maybe the #+begin_equation should be a built-in block in org-mode,
> also with a fast template (maybe "<eq").
>
> --
> Darlan Cavalcante
>
> At Thu, 16 Jun 2011 08:53:24 +0100,
> Eric S Fraga <e.fraga@ucl.ac.uk> wrote:
>
>> Samuel Sinayoko <s.sinayoko@soton.ac.uk> writes:
>>
>>
>>> Dear list,
>>>
>>> I've been trying to write short scientific reports that I can export to
>>> both LaTeX and HTML. So far I've managed to figure out how to include
>>> equations, images, references, and how to include labels and cross
>>> reference between all these things.
>>>
>>> The only problem I have is that I can't get numbered equations in both
>>> LaTeX and HTML. Using the snippet below, I'm able to get a numbered
>>> equation in HTML but not in LaTeX. I've put
>>> loadFiles: ["extensions/eqn-number.js"],
>>> in jsMath/easy/load.js. If I replace the $$ by
>>> \begin{equation} and \end{equation}, I get a numbered equation in LaTeX
>>> but not in HTML.
>>>
>>> How can I get numbered equations in both HTML and LaTeX?
>>>
>> I can't help you wish HTML unfortunately but I can summarise the issue
>> in LaTeX.
>>
>> With the standard document class (article say), equations can be either
>> "displayed" or "inline". Only displayed equations are numbered and then
>> only if you use =equation= (or =align=, =eqnarray=, etc). $$ ... $$ is
>> equivalent to \[ ... \] which is essentially equivalent to the
>> unnumbered version of \begin{equation} (aka \begin{equation*}).
>>
>> The trick would be to get the HTML exporter to apply the same processing
>> to \begin{equation} ... \end{equation} as it does to $$ ... $$, I guess?
>> --
>> : Eric S Fraga (GnuPG: 0xC89193D8FFFCF67D) in Emacs 24.0.50.1
>> : using Org-mode version 7.5 (release_7.5.399.g01eb)
>>
>>
```