katex produces extra phantom output in rmarkdown::html_vignette

[kgoldfeld]

I have used katex successfully in R blogdown when creating html output. However, I am running into a problem when creating a vignette for an R package that is being output to an rmarkdown::html_vignette. Here's the yaml:

---
title: "Correlation Matrices"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Correlation Matrices}
  %\VignetteEngine{knitr::rmarkdown}
  \usepackage[utf8]{inputenc}
---

And here is the katex-related code:

matform <- "
R = \\left (
\\begin{matrix} 
1.0 & \\rho & \\rho & \\rho \\\\
\\rho & 1.0 & \\rho & \\rho \\\\
\\rho & \\rho & 1.0 & \\rho \\\\
\\rho & \\rho & \\rho & 1.0
\\end{matrix}
\\right )
"

katex::katex_html(matform)

And the correct matrix is generated in the html output file, but there is extra output that shows up:

The centered matrix on top is what I am trying to create. The "inline" piece below is not desired. Is this a bug, or have I implemented incorrectly? Thanks so much.

[jeroen]

I can't reproduce this, it seems to work fine for me?

Is there perhaps something else in your vignette that could be interfering? Do you see the same problem with an empty vignette with only this equation? Are you using the latest version of katex from cran?

[kgoldfeld]

I was missing the include_css = TRUE argument. In blogdown, where I first used katex, the output was generated as expected without explicitly specifying include_css. But, I am very glad to have this resolved. Thanks so much.