Katex: \begin{align} not support

[nyiuang]

I want to use KaTex instead Mathjax, but the existed formula contain begin{align}, it cannot render with KaTex

[edemaine]

You can use \begin{aligned} within math mode. Does this suit your purpose?

[nyiuang]

@edemaine the formulas has already exist in database, should I use RegExp to covert align to aligned? Im worry that if there are some other incompatible formulas grammar between latex and katex

[edemaine]

If the formulas are already supposed to be in math mode, then you should be using aligned instead of align. Yes, a regex would work.

If you have \begin{align} ... \end{align} at the text level, i.e., instead of \[ ... \] or something similar, then that is at least correct at the LaTeX level, and you're really looking for a solution to #604. Until that time, a regex replacing \begin{align} with \[\begin{aligned} and \end{align} with \end{aligned}\] would work as a stopgap.

[nyiuang]

thanks，and one more question: in #604 I see the solution to "align",and are there some other risk of incompatible formulas grammar between latex and katex ?

[wookayin]

Katex renders aligned weirdly. To support a compatibility with other grammars (latex), please make \begin{align}..\end{align} work.

e.g.

$$
\begin{aligned}
V^*(s) &=  \max_a \Big( \underbrace{r(s, a) + \gamma V^*(s')}_{=Q^*(s, a)} \Big)
\end{aligned}
$$