Katex Parse Error when viewing Org Roam note on Org Roam UI
reddit / emacs

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waterstrider123 · 2022-04-16 14:46

I have a org roam note that presents matrix multiplication and it
looks fine in org mode as shown below.

https://preview.redd.it/nqazc9rjlwt81.png?width=310&format=png&auto=we
bp&s=8a559a18802177d7fa7ca96f8532fd3f8186cefd

However, when I run org-roam-ui, the browser does not show the matrix
multiplication in the correct format. It just gives me the latex
syntax as shown below. It works fine when I am just presenting
equations, but it does not seem to work properly for matrix
multiplications.

https://preview.redd.it/jdsvwvjukwt81.png?width=636&format=png&auto=we
bp&s=c2d0d03ed61e5abce7f83f778fc20dc77593b14c

When I hover over the red text, I get the following info and I am
wondering why this works on org mode but not with org-roam-ui.

https://preview.redd.it/gre7e6uzlwt81.png?width=634&format=png&auto=we
bp&s=a94a90a90e517b344a7bd9a500b24664f8cd963c

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lebensterben · 2022-04-16 14:55

you should report this to org-roam

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Tommerd · 2022-04-17 08:03

Hey! Org-roam-ui guy here.

The reason this happens is because KaTeX, the web-based latex
processing thingy, only parses a subset of all latex commands.
 \begin{document} is for entire latex documents, while KaTeX only does
math. Similar environments such as mini page etc also don't work.

I think simply removing the document env should work here! You already
have the \[ \] delineators so you really don't need it, unless it's a
standalone latex documents you're trying to render, in which case:
don't do that lol.

If you really want environments you can use \begin{equation}

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waterstrider123 · 2022-04-20 22:26

I replaced \\begin{document} with \\begin{equation}, but I still get
the same issue even though it renders properly in the org file and not
in the ui:

    \begin{equation}
    \[
        h_{\theta}(x) =
        \left[
        \begin{array}{ccccc}
            \theta_{0} & \theta_{1} & \theta_{2} & \hdots &
\theta_{n}\\
        \end{array}
        \right]

        \begin{bmatrix}
            x_{1} \\
            x_{2} \\
            \vdots \\
            x_{m}
        \end{bmatrix}
        = \theta^{T}x
    \]
    \end{equation}

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Tommerd · 2022-04-21 08:31

No you need to either have \begin{equation}...\end{equation} or
\[...\], not both.

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waterstrider123 · 2022-04-21 23:16

Thanks, it works now.

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Tommerd · 2022-04-22 08:09

Great! :D