how to add a caption to a latex equation?

[hopezh]

Description

May I ask how to add a caption to a latex equation like the following?

I'm unable to find a reference in the quarto doc on latex figure.

[mcanouil]

If you look for equation related things in the figure section of the documentation, you are very unlikely to find what you want.
See https://quarto.org/docs/authoring/cross-references.html#equations for what's currently possible.

[mcanouil]

Additionally:

• Using captions on math figures (LaTeX) jgm/pandoc#8145
• Epic: Crossref Overhaul #4944 (work ongoing here should/will allow more flexibility that is currently not allowed in Pandoc/Quarto)

[s2t2]

So how to answer this question, though? The links don't seem to provide a working example of how to add a caption to an equation.

This might be a reasonable workaround for adding a caption to an equation:

::: {.equation #eq:simple-equation}
$$
\frac{x+2}{3x+6} = \frac{1(x+2)}{3(x+2)} = \frac{1}{3}
$$
*Equation 1: Simplification of the equation*
:::

[cscheid]

The links don't seem to provide a working example of how to add a caption to an equation.

That's because it's a feature that Quarto doesn't support.

[mcanouil]

Use a custom cross-reference, see https://quarto.org/docs/authoring/cross-references-custom.html#pdf-output.

---
title: "Quarto Playground"
format: pdf
crossref:
  custom:
    - kind: float
      reference-prefix: Equation
      key: eqn
      latex-env: eqn
---

::: {#eqn-simplify}
$$
\frac{x+2}{3x+6} = \frac{1(x+2)}{3(x+2)} = \frac{1}{3}
$$

Simplification of the equation
:::