Equation number alignment

[lu-kas]

Bug description

This is a (potential) bug for a book project. The number alignment of a labeled equation does change if I explicitly set the html-math-method to mathjax (which is AFAIK the default).

1. If the html-math-method is not set, the equation number is right aligned. This is the behavior I'm interested in.
2. If the variable is set to mathjax, the equation number is directly after the equation.

Background: I need to set this option, as I need to specify an individual MathJax URL.

Steps to reproduce

_quarto.yml:

project:
  type: book

book:
  title: "equation test"
  author: "Nobody"
  date: "5/18/2025"
  chapters:
    - index.qmd


format:
  html:
    # comment/remove the following option to trigger the change in behavior
    html-math-method:
      method: mathjax
    theme:
      - cosmo
      - brand

index.qmd:

# Preface {.unnumbered}

$$
\alpha = \beta
$$ {#eq-ab}

This is @eq-ab.

Actual behavior

The equation number is directly after the equation.

Expected behavior

The equation number should be right alligned.

Your environment

• OS: MacOS 15.4.1 (24E263)
• IDE: none

Quarto check output

Quarto 1.7.28
[✓] Checking environment information...
      Quarto cache location: /Users/.../Library/Caches/quarto
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.6.3: OK
      Dart Sass version 1.85.1: OK
      Deno version 1.46.3: OK
      Typst version 0.13.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.7.28
      Path: /Applications/quarto/bin

[✓] Checking tools....................OK
      TinyTeX: (not installed)
      Chromium: (not installed)

[✓] Checking LaTeX....................OK
      Tex:  (not detected)

[✓] Checking Chrome Headless....................OK
      Using: Chrome found on system
      Path: /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
      Source: MacOS known location

[✓] Checking basic markdown render....OK

[✓] Checking Python 3 installation....OK
      Version: 3.9.6
      Path: /Applications/Xcode.app/Contents/Developer/usr/bin/python3
      Jupyter: (None)

      Jupyter is not available in this Python installation.
      Install with python3 -m pip install jupyter

[✓] Checking R installation...........OK
      Version: 4.1.3
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Library/Frameworks/R.framework/Versions/4.1-arm64/Resources/library
      knitr: 1.38
      rmarkdown: 2.13

[✓] Checking Knitr engine render......OK

[mcanouil]

Please carefully read the documentation.
method is expected to be accompanied by a url.

https://quarto.org/docs/output-formats/html-basics.html#latex-equations

---
format: html
html-math-method: mathjax
---

$$
\alpha = \beta
$$ {#eq-ab}

This is @eq-ab.

[mcanouil]

Quarto 1.7.28

If you intend to use pre-releases, please be sure to update regularly, especially when opening an issue.

[lu-kas]

Thanks for your support and quick response.

I have spent a lot of time reading the documentation and searching the web before posting this issue -- but obviously not properly. Having a look again to the documentation you have pointed to, I have used the provided example:

---
format: html
html-math-method:
  method: mathjax
  url: "https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"
---

$$
\alpha = \beta
$$ {#eq-ab}

This is @eq-ab.

However, this still changes the / my expected behavior.

Thanks, again.

[mcanouil]

Thanks.
It seems to be kind of by design.

I'm reopening because I see a way to ensure the addition of the numbering remains constant regardless of how MathJax/KaTeX methods are set.

• quarto-cli/src/resources/filters/crossref/equations.lua

  Lines 64 to 72 in 26fa297

  	local eqNumber = eqQquad
  	local mathMethod = param("html-math-method", nil)
  	if _quarto.format.isHtmlOutput() and (mathMethod == "mathjax" or mathMethod == "katex") then
  	eqNumber = eqTag
  	end
  	eq.text = eq.text .. " " .. eqNumber(inlinesToString(numberOption("eq", order)))
  	local span = pandoc.Span(eq, pandoc.Attr(label))
  	targetInlines:insert(span)
  	end

It seems the param("html-math-method", nil) does not read html-math-method.method:

• quarto-cli/src/resources/filters/crossref/equations.lua

  Line 65 in 26fa297

  local mathMethod = param("html-math-method", nil)

Which lead to the use of \qquad(1) and not \tag{1}.

So here the enhancement would be to check for html-math-method.method when set in addition to html-math-method.