Converting a paragraph containing an equation from org to latex results in 3 paragraphs

[METhOphetamine]

Problem description

Converting a paragraph containing an equation from org to latex results in 3 paragraphs, because pandoc inserts a newline before and after the equation. For example this org file:

Some equation here
\begin{equation}
x = y
\end{equation}
where $x$ is something important

Gets converted to the following latex code:

Some equation here

\begin{equation}
x = y
\end{equation}

where \(x\) is something important

But if we use emacs' org-mode for the conversion, we get this latex code:

Some equation here
\begin{equation}
x = y
\end{equation}
where \(x\) is something important

So it should be considered a bug.

You also get the same issue when using the \begin{subequations} and \begin{math} blocks.

Pandoc version?

3.6.4

I also tested it in the online version.

Links to similar issues

Markdown had similar issues in the past.

#7883

#3726

#894

#2171

[jgm]

Notice this difference:

% pandoc -f latex -t native
Some equation here
\begin{equation}
x = y
\end{equation}
where $x$ is something important
^D
[ Para
    [ Str "Some"
    , Space
    , Str "equation"
    , Space
    , Str "here"
    , SoftBreak
    , Math DisplayMath "x = y"
    , SoftBreak
    , Str "where"
    , Space
    , Math InlineMath "x"
    , Space
    , Str "is"
    , Space
    , Str "something"
    , Space
    , Str "important"
    ]
]

% pandoc -f org -t native
Some equation here
\begin{equation}
x = y
\end{equation}
where $x$ is something important
^D
[ Para
    [ Str "Some" , Space , Str "equation" , Space , Str "here" ]
, RawBlock
    (Format "latex")
    "\\begin{equation}\nx = y\n\\end{equation}\n"
, Para
    [ Str "where"
    , Space
    , Math InlineMath "x"
    , Space
    , Str "is"
    , Space
    , Str "something"
    , Space
    , Str "important"
    ]
]

Potential solution: have the org reader handle the equation environment like the latex reader does, treating it as regular display math. This would facilitate conversion to many formats besides LaTeX. However, it would mean losing the equation number on export to LaTeX.

[jgm]

A different solution would be to parse the equation environment as RawInline rather than RawBlock.

[METhOphetamine]

For me personally losing the equation numbers would be a defeat the reason to use equations at all. Might as well use inline math at that point, if I cannot properly reference it. I'm guessing it would be fine for \begin{math} environment, because that isn't numbered. But I don't use that environment, so I don't know.

I'm guessing you don't want your codebase polluted with sed hacks but my workaround is to use the following sed command before converting the org file with pandoc:

sed -e 's \\end{subequations} \\end{subequations}\n\\noindent{}\\ignorespaces g' file.org | pandoc -o file.tex

(same with normal equations) This does not get rid of the paragraphs, but the reader won't notice because the paragraphs just look like newlines or at least aren't indented. The \ignorespaces macro is required because pandoc adds a single space after the \noindent{} macro which then looks like a paragraph indented with a single space.

[METhOphetamine]

Yikes sorry, I accidentally closed it. I'm a github noob.

A different solution would be to parse the equation environment as RawInline rather than RawBlock.

Regarding this, I don't know what that would mean. I'm not similar with the codebase, sorry.

[jgm]

If you want something without sed, you could put something in header-includes that uses etoolbox tools to add the \noindent\ignorespaces to the end of these environments.

Making it a RawInline would case the environment to appear inside the paragraph as part of its contents, which is what you want. So that might be a worth while change, and it's probably not a difficult one.

[jgm]

OK, I think I've fixed this in a satisfactory way. @tarleb let me know if I've made some blunder.
This does change how raw TeX is handled in an inline environment, but in the direction of closer conformity to org-mode, as far as I can see.

[METhOphetamine]

If you want something without sed, you could put something in header-includes that uses etoolbox tools to add the \noindent\ignorespaces to the end of these environments.

Thanks for the tip!

And obviously thanks for fixing it!

[tarleb]

Thanks for the fix, LGTM.

I'm slowly catching up on the most pressing tasks, might take me while.