title: $:/plugins/tiddlywiki/katex/usage

!! Reference:

# Mathematical typesetting: [ext[https://katex.org/docs/supported.html]]
# Chemical typesetting: [ext[https://mhchem.github.io/MathJax-mhchem/]]

!! Syntax

The usual way to include ~LaTeX is to use `$$` (when copying code examples from the references above, you will need to change from `$` to `$$`). For example:

```
$$\displaystyle f(x) = \int_{-\infty}^\infty\hat f(\xi)\,e^{2 \pi i \xi x}\,d\xi$$
```

$$\displaystyle f(x) = \int_{-\infty}^\infty\hat f(\xi)\,e^{2 \pi i \xi x}\,d\xi$$

chemical:

```
$$\ce{Hg^2+ ->[I-] HgI2 ->[I-] [Hg^{II}I4]^2-}$$
```

$$\ce{Hg^2+ ->[I-] HgI2 ->[I-] [Hg^{II}I4]^2-}$$

Single line equations will render in inline mode. If there are newlines between the `$$` delimiters, the equations will be rendered in display mode.

The underlying widget can also be used directly, giving more flexibility:

```
<$latex text="f(x) = \int_{-\infty}^\infty\hat f(\xi)\,e^{2 \pi i \xi x}\,d\xi" displayMode="true"></$latex>
```

<$latex text="f(x) = \int_{-\infty}^\infty\hat f(\xi)\,e^{2 \pi i \xi x}\,d\xi" displayMode="true"></$latex>

The KaTeX widget is provided under the name `<$latex>` and is also available under the alias `<$katex>`. It's better to use the generic `<$latex>` name unless you are running multiple ~LaTeX plugins and wish to specifically target KaTeX.

!! Macro

Tiddlers with tag `$:/tags/KaTeX/Macro` will be recognized as global KaTeX macros. You can create new macro using the form in the [[config|$:/plugins/tiddlywiki/katex/config]].