remark-math

remark and rehype plugins to support math!

Install

npm:

npm install remark-math rehype-katex

Use

Say we have the following file, example.md:

Lift($L$) can be determined by Lift Coefficient ($C_L$) like the following
equation.

$$
L = \frac{1}{2} \rho v^2 S C_L
$$

And our script, example.js, looks as follows:

const vfile = require('to-vfile')
const unified = require('unified')
const markdown = require('remark-parse')
const math = require('remark-math')
const remark2rehype = require('remark-rehype')
const katex = require('rehype-katex')
const stringify = require('rehype-stringify')

unified()
  .use(markdown)
  .use(math)
  .use(remark2rehype)
  .use(katex)
  .use(stringify)
  .process(vfile.readSync('example.md'), function (err, file) {
    if (err) throw err
    console.log(String(file))
  })

Now, running node example yields:

<p>Lift(<span class="math math-inline"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>L</mi></mrow><annotation encoding="application/x-tex">L</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.68333em;vertical-align:0em;"></span><span class="mord mathnormal">L</span></span></span></span></span>) can be determined by Lift Coefficient (<span class="math math-inline"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>C</mi><mi>L</mi></msub></mrow><annotation encoding="application/x-tex">C_L</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.83333em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathnormal" style="margin-right:0.07153em;">C</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.32833099999999993em;"><span style="top:-2.5500000000000003em;margin-left:-0.07153em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">L</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span></span>) like the following equation.</p>
<div class="math math-display"><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>L</mi><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mi>ρ</mi><msup><mi>v</mi><mn>2</mn></msup><mi>S</mi><msub><mi>C</mi><mi>L</mi></msub></mrow><annotation encoding="application/x-tex">L = \frac{1}{2} \rho v^2 S C_L</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.68333em;vertical-align:0em;"></span><span class="mord mathnormal">L</span><span class="mspace" style="margin-right:0.2777777777777778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2777777777777778em;"></span></span><span class="base"><span class="strut" style="height:2.00744em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.32144em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord mathnormal">ρ</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.03588em;">v</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641079999999999em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span><span class="mord mathnormal" style="margin-right:0.05764em;">S</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.07153em;">C</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.32833099999999993em;"><span style="top:-2.5500000000000003em;margin-left:-0.07153em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">L</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span></span></div>

Wow, that’s a lot! But in a browser, that looks something like this:

Note: you should also use katex.css somewhere on the page to style math properly:

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/katex.min.css" integrity="sha384-AfEj0r4/OFrOo5t7NnNe46zW/tFgW6x/bCJG8FqQCEo3+Aro6EYUG4+cU+KJWu/X" crossorigin="anonymous">

Packages

This repo houses four packages:

• remark-math — Parses $ as inlineMath and $$ as math nodes
• rehype-katex — Transforms math nodes with KaTeX (✨ recommended)
• rehype-mathjax — Transforms math nodes with MathJax (✨ recommended)
• remark-html-katex — Transforms math nodes with KaTeX for remark-html (discouraged)

See their readmes for more information.

Security

Use of rehype-katex, rehype-mathjax, or remark-html-katex renders user content with KaTeX, so any vulnerability in KaTeX can open you to a cross-site scripting (XSS) attack.

Always be wary of user input and use rehype-sanitize.

Related

• remark-breaks – Support hard breaks without needing spaces (like on issues)
• remark-gfm — GFM (autolink literals, strikethrough, tables, tasklists)
• remark-github — Autolink references like in GitHub issues, PRs, and comments
• remark-footnotes — Footnotes
• remark-frontmatter — Frontmatter (YAML, TOML, and more)

Contribute

See contributing.md in remarkjs/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.

License

MIT © Junyoung Choi