How can I wrap the subscript into a math environment in Org-mode?

How can I wrap the subscript into a math environment in Org-mode?

[Lei Zhe]

I have some subscripts in my org file like B_25, B_30. These
subscripts can be exported to LaTeX like B_{25}, B_{30}. However, I
want part of the subscripts like B to be exported as italic /B/. As
one solution for this, I can wrap these thing into a math environment
like \(B_{25}\). But since my file contains large numbers of these
subscripts, I would like to implement this in a programmable way.

I found a subscript filter function in org-mode, so I tried to use it
to wrap the subscripts by

(defun wrap-subscript-with-math-environment (contents backend info)
  (when (eq backend 'latex)
   (format "\\(%s\\)" contents)))

(add-to-list 'org-export-filter-subscript-functions
'wrap-subscript-with-math-environment)
However, the results exported are like B\($_{\text{25}}$ \). It seems
like the subscript filter contents only contain _25 part. Does anyone
have some solutions about this?

Re: How can I wrap the subscript into a math environment in Org-mode?

[John Kitchin]

it sounds like you are looking for a way to conveniently entering
equations in LaTeX to me. This is seems like a case where you cannot
have it both ways, that is convenient subscripts in math and text that
are easy to tell the difference between, e.g. in H_{2}O you do not want
the letters in math mode, but in e^{x}=3 you do. It is hard to see how a
filter function would always do the right thing here.

The easiest thing is probably to make a function to make it simple to
add equations, e.g. this function will wrap a selected region in $$ (or
\(\) with a prefix arg) or insert those so you can type in the equation.
I bind it to super-4 which is pretty easy to use. you could also try
some kind of yasnippet approach.

(defun latex-math-region-or-point (&optional arg)
  (interactive "P")
  (let ((chars (if arg
                   '("\\(" . "\\)")
                 '("$" . "$"))))

    (if (region-active-p)
        (progn
          (goto-char (region-end))
          (insert (car chars))
          (goto-char (region-beginning))
          (insert (cdr chars)))
      (insert (concat  (car chars) (cdr chars)))
      (backward-char (length (cdr chars))))))

(define-key global-map (kbd "s-4") 'latex-math-region-or-point)



Lei Zhe writes:

> I have some subscripts in my org file like B_25, B_30. These
> subscripts can be exported to LaTeX like B_{25}, B_{30}. However, I
> want part of the subscripts like B to be exported as italic /B/. As
> one solution for this, I can wrap these thing into a math environment
> like \(B_{25}\). But since my file contains large numbers of these
> subscripts, I would like to implement this in a programmable way.
>
> I found a subscript filter function in org-mode, so I tried to use it
> to wrap the subscripts by
>
> (defun wrap-subscript-with-math-environment (contents backend info)
>   (when (eq backend 'latex)
>    (format "\\(%s\\)" contents)))
>
> (add-to-list 'org-export-filter-subscript-functions
> 'wrap-subscript-with-math-environment)
> However, the results exported are like B\($_{\text{25}}$ \). It seems
> like the subscript filter contents only contain _25 part. Does anyone
> have some solutions about this?

--
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