August 25, 2018

I’ve previously posted about Blogging with Jupyter in a previous post. For the latest post on LearningJulia I needed one additional feature: LaTeX equation numbering in Jupyter. Here’s how I got that to work.

Getting LaTeX Equation Numbering in Jupyter Notebooks

LaTeX natively supported in Markdown editing in a Jupyter notebook through MathJax. Getting it to work in Jupyter notebooks involves installing the jupyter_contrib_nbextensions package.

These instructions are taken from the official install docs, and they worked for me.

pip install jupyter_contrib_nbextensions
jupyter contrib nbextension install --user
jupyter nbextension enable equation-numbering/main

Then, restarting the jupyter kernel enables the extension. To get the numbered equations to show up in a markdown notebook, just use LaTeX syntax:

\begin{equation}
H u - v = 0
\end{equation}

\begin{equation}
\begin{bmatrix}
h_1 & h_2 & h_3 \\
h_4 & h_5 & h_6 \\
h_7 & h_8 & h_9
\end{bmatrix}\begin{bmatrix}
u_1 \\ u_2 \\ 1
\end{bmatrix}
-
\begin{bmatrix}
v_1 \\ v_2 \\ 1
\end{bmatrix} = 0
\end{equation}

This is the result!

The only downside of this extension is that every time you re-compile a cell with equation numbering, the numbers keep incrementing. The good part is that the extension comes with a way to fix this problem: a little widget at the top of the notebook appears. When you click it, the numbering is restarted:

Pretty cool, right?

Getting LaTeX Equation Numbering in nbconvert

Automatically, nbconvert will apply these new extensions. The one thing it won’t do is apply the correct MathJax settings in the style. To do that, all I needed was to add these lines:

<script type="text/x-mathjax-config">
MathJax.Hub.Config({
    TeX: {
        equationNumbers: { autoNumber: "AMS" }
    }
});
</script>

to the exported .html file after running nbconvert. And the result works great!

You can read the full blog post here to learn what all these equations mean.

Conclusion

I hope this helps someone else, or at the very least, future me!