Links to LaTeX equations

Links to LaTeX equations

[Fraga, Eric]

Hello all,

it's that time of year where I have to think about revamping my lecture
slides (having just finished one year, the next one starts...).  I write
these in org and export to beamer obviously!

I teach a technical subject.  I therefore have quite a few equations in
my slides and I use LaTeX for these.  I would like to be able to use org
fully with respect to links and targets.  If I define a label in LaTeX
directly, \label{an-equation} for instance, I get no benefit from using
an org link to it, e.g. [[an-equation]] (by default, this leads to the
org exporter complaining about a missing target and if I tell org not to
complain I subsequently miss real errors).  So I use inline LaTeX to
provide the link, as in \ref{an-equation}.  But then I lose the ability
to jump to the target within org, something which is quite useful given
that I have many slides for the full module I teach.

The only satisfactory solution I have found is to do something along
these lines:

#+begin_src org
  The equation is:
  ,#+begin_equation
  <<an-equation>>
  y = x + 3
  ,#+end_equation

  (later) In equation [[an-equation]], we see nothing much.
#+end_src

This works in that I can jump to the label by clicking on the link but I
lose the ability to edit the equation in LaTeX mode.

Any pointers would be welcome.

Thanks,
eric

-- 
Eric S Fraga via Emacs 27.0.50, Org release_9.2.4-379-g1b74ae

Re: Links to LaTeX equations

[Ken Mankoff]

Hi Eric,

On 2019-06-28 at 10:55 -02, Fraga, Eric <e.fraga@ucl.ac.uk> wrote...
> I would like to be able to use org fully with respect to links and
> targets. If I define a label in LaTeX directly, \label{an-equation}
> for instance, I get no benefit from using an org link to it, e.g.
> [[an-equation]]

Why don't you define the link in Org?

#+NAME: eq:foo
\begin{equation}
foo
\end{equation}

  -k.

Re: Links to LaTeX equations

[Fraga, Eric]

On Friday, 28 Jun 2019 at 11:58, Ken Mankoff wrote:
> Why don't you define the link in Org?
>
> #+NAME: eq:foo
> \begin{equation}

And why are the obvious solutions not those that come to mind (for
me)????

Many thanks.  Nothing in the documentation to even suggest this
possibility.  That's my excuse. :)
-- 
: Professor Eric S Fraga, http://www.homepages.ucl.ac.uk/~ucecesf
: Required hieroglyphics follow: ∀ε>0,∃δ>0∋|x-x₀|<δ⇒|f(x)-f(x₀)|<ε

Re: Links to LaTeX equations

[John Kitchin]

[-- Attachment #1: Type: text/plain, Size: 2082 bytes --]

Org-ref provides a ref link for exactly this purpose. It looks like
ref:an-equation and if you click on it it jumps to the label. The link is
red if the label doesn't exist and maroonish if it does. It exports in
latex as \ref{an-equation}. It sounds like just what you need.

You can get org-ref on melpa.

On Fri, Jun 28, 2019 at 9:15 AM Fraga, Eric <e.fraga@ucl.ac.uk> wrote:

> Hello all,
>
> it's that time of year where I have to think about revamping my lecture
> slides (having just finished one year, the next one starts...).  I write
> these in org and export to beamer obviously!
>
> I teach a technical subject.  I therefore have quite a few equations in
> my slides and I use LaTeX for these.  I would like to be able to use org
> fully with respect to links and targets.  If I define a label in LaTeX
> directly, \label{an-equation} for instance, I get no benefit from using
> an org link to it, e.g. [[an-equation]] (by default, this leads to the
> org exporter complaining about a missing target and if I tell org not to
> complain I subsequently miss real errors).  So I use inline LaTeX to
> provide the link, as in \ref{an-equation}.  But then I lose the ability
> to jump to the target within org, something which is quite useful given
> that I have many slides for the full module I teach.
>
> The only satisfactory solution I have found is to do something along
> these lines:
>
> #+begin_src org
>   The equation is:
>   ,#+begin_equation
>   <<an-equation>>
>   y = x + 3
>   ,#+end_equation
>
>   (later) In equation [[an-equation]], we see nothing much.
> #+end_src
>
> This works in that I can jump to the label by clicking on the link but I
> lose the ability to edit the equation in LaTeX mode.
>
> Any pointers would be welcome.
>
> Thanks,
> eric
>
> --
> Eric S Fraga via Emacs 27.0.50, Org release_9.2.4-379-g1b74ae
>
-- 
John

-----------------------------------
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
@johnkitchin
http://kitchingroup.cheme.cmu.edu

[-- Attachment #2: Type: text/html, Size: 2865 bytes --]

Re: Links to LaTeX equations

[Fraga, Eric]

On Friday, 28 Jun 2019 at 10:19, John Kitchin wrote:
> Org-ref provides a ref link for exactly this purpose. 

Thanks John.  I've looked at org-ref before and it looks nice.  However,
due to my organically grown org (and Emacs) customizations (over 35
years...), I couldn't get it to work well for me.  Yes, I must clean up
my .emacs some day!

Using #+name: does the job for the moment.

Thanks again,
eric

-- 
Eric S Fraga via Emacs 27.0.50, Org release_9.2.4-379-g1b74ae

Re: Links to LaTeX equations

[Carsten Dominik]

[-- Attachment #1: Type: text/plain, Size: 656 bytes --]

On Fri, Jun 28, 2019 at 4:46 PM Fraga, Eric <e.fraga@ucl.ac.uk> wrote:

> On Friday, 28 Jun 2019 at 11:58, Ken Mankoff wrote:
> > Why don't you define the link in Org?
> >
> > #+NAME: eq:foo
> > \begin{equation}
>
> And why are the obvious solutions not those that come to mind (for
> me)????
>
> Many thanks.  Nothing in the documentation to even suggest this
> possibility.  That's my excuse. :)
>

It kind-of is documented, in section 4.2.  Is that unclear?

Carsten


> --
> : Professor Eric S Fraga, http://www.homepages.ucl.ac.uk/~ucecesf
> : Required hieroglyphics follow: ∀ε>0,∃δ>0∋|x-x₀|<δ⇒|f(x)-f(x₀)|<ε
>

[-- Attachment #2: Type: text/html, Size: 1308 bytes --]