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rmatrixr-markdownpandocmathml

How do I get (LaTeX math) typeset matrix with borders in HTML output from *.Rmd?

The following rmarkdown works fine when compiling to PDF (via LaTeX), but not when compiling to HTML (via Markdown).

PDF (via LaTeX)

---
title: "test"
author: "Maximilian Held"
output: pdf_document
documentclass: memoir
---

(@matrix-test2) $$
\bordermatrix{
  ~       & Petra & Ingrid \cr
  Petra   & 1     & 0 \cr
  Ingrid  & 0     & 1 \cr
}
$$

tex

HTML (via Markdown)

---
title: "test"
author: "Maximilian Held"
output: html_document
documentclass: memoir
---

(@matrix-test2) $$
\bordermatrix{
  ~       & Petra & Ingrid \cr
  Petra   & 1     & 0 \cr
  Ingrid  & 0     & 1 \cr
}
$$

yields

html

What's up with that and on whose end is this (Pandoc? Markdown? MathML?)

Solution

  • knitr, the tool normally used to convert RMarkdown to HTML/PDF (from LaTeX)/DOCX, uses Pandoc. Pandoc is a nice tool to convert Markdown to HTML and LaTeX and allows you to use LaTeX math environments inside Markdown, e.g.

    $a x^2 + b x + c = 0$

    or

    $$a x^2 + b x + c = 0$$

    or

    \begin{equation}
a x^2 + b x + c = 0
\end{equation}

    are properly converted by Pandoc. Pandoc also supports the amsmath, a very popular LaTeX package for math. Unfortunately, Pandoc doesn't support all (La)TeX commands/environment as you discovered.

    What I always do when working with Pandoc is try to keep things simple. In the case you present, I would use normal tables instead of a matrix.