benrbray
commented
3 years ago I agree, this is a common pain point for me as well, and I've been mulling over solutions in my head for a while. Getting the workflow right is tricky, but I'm happy to discuss possibilities. Although the examples you listed share a common syntax, I think they appear in quite different contexts and will need to be handled differently. We will also be limited by the commands supported by KaTeX / MathJax.
- Matrices tend to appear as subexpressions of a larger math block, and more than one matrix may appear in a single expression. How should the editor behave for something like this?
A x = \begin{bmatrix}
a_{11} & a_{12} \\
a_{21} & a_{22}
\end{bmatrix}
\begin{bmatrix}
x_1 \\ x_2
\end{bmatrix}-
Tables tend to appear by themselves, so it might be as simple as enabling prosemirror-tables extension with some special code for serialization to LaTeX.
-
I suspect that everyone has different preferences for how to format multi-line derivations, so it might be difficult to standardize, especially when nested brackets are involved. Personally I tend to use multiple indented lines for nested brackets, and I'll often wrap manually if lines get too long. For example,
\begin{aligned}
\EE_{q(x)}\left[ (x-\mu_A)^T \Sigma_A^{-1} (x-\mu_A) \right]
&= \EE\left[
\trace\left( (x-\mu_A)^T \Sigma_A^{-1} (x-\mu_A) \right)
\right]
& \text{(trace of scalar)} \\
&= \EE\left[
\trace\left( \Sigma_A^{-1} (x-\mu_A) (x-\mu_A)^T \right)
\right]
& \text{(cyclicity)}\\
&= \trace\left( \EE\left[
\Sigma_A^{-1} (x-\mu_A) (x-\mu_A)^T
\right] \right)
&\text{(linearity)}\\
&= \trace\left( \Sigma_A^{-1} \EE\left[
(x-\mu_A) (x-\mu_A)^T
\right] \right)
&\text{(linearity)}\\
&= \trace\left( \Sigma_A^{-1} \left[
\Sigma_B + (\mu_B - \mu_A)(\mu_B - \mu_A)^T
\right] \right)
&\text{(eqn\;\ref{eqn:gauss-quadratic-form})} \\
&= \trace\left( \Sigma_A^{-1} \Sigma_B \right)
+ (\mu_B - \mu_A)^T \Sigma_A^{-1} (\mu_B - \mu_A)
&\text{(cyclicity; linearity)}
\end{aligned}- Commutative diagrams are tricky, because neither KaTeX nor MathJax has great support for them out of the box. It would be helpful to collect some examples of source code for commutative diagrams that we expect
prosemirror-mathto be able to handle. The best tool I know of for editing commutative diagrams on the web is quiver, so worst case we might be able to introduce a new type of math node that makes it easy to embed diagrams made with quiver.
bohrium
One of the most annoying-times-frequency things among my latex experiences is making 2d grids by describing them using 1d text. Such grids include matrices, commutative diagrams, tables, multi-line derivations whose terms are aligned, and more. It'd be neat to provide a special "array mode" for parsing and editing text of the form
This is the syntax for the latex body in each of all four examples above. The cells(' latex expressions) will typically all differ in length, creating a headache (do we spend time inserting white-space to align the columns, maintaining this alignment when we modify the cells? or do we ignore alignment issues in the source code and just count in our head when editing each row?)
It would be nice if when one's cursor enters a latex block of the above form, the cells in the latex block automatically align (wrt the ampersands and line-break symbols). If I correctly understand the spirit of prosemirror-math, one wants to avoid having popup dialog boxes or editors separate from the text. So perhaps the alignment could be as simple as inserting appropriate whitespace when the block is "active"!