mathjaxr: Using Mathjax in Rd Files

R build status CRAN Version devel Version

Description

The mathjaxr package allows for easy inclusion of MathJax equations in Rd files. Package authors wanting to make use of the package and its functionality need to:

  1. install the mathjaxr package,
  2. add mathjaxr to Imports in the DESCRIPTION file of their package,
  3. add mathjaxr to RdMacros in the DESCRIPTION file of their package (or add RdMacros: mathjaxr if the DESCRIPTION file does not yet contain a RdMacros entry),
  4. add import(mathjaxr) in the NAMESPACE file of their package.

One can then enable the use of MathJax by calling the \loadmathjax macro (that is provided by the mathjaxr package) within the \description{} section of an Rd file (or within the @description section when using roxygen2).

An inline equation can then be added with the \mjeqn{latex}{ascii} macro, with the LaTeX commands for the equation given between the first set of curly brackets (which will be rendered in the HTML and PDF help pages) and the plain-text version of the equation given between the second set of curly brackets (which will be shown in the plain text help). With the \mjdeqn{latex}{ascii} macro, one can add ‘displayed equations’ (as in LaTeX’s displaymath environment).

Single argument versions of these macros, \mjseqn{latexascii} and \mjsdeqn{latexascii}, are also available. For the relatively rare case that one must specify different LaTeX commands for the PDF and HTML pages, there are also triple argument versions of these macros, namely \mjteqn{pdflatex}{htmllatex}{ascii} and \mjtdeqn{pdflatex}{htmllatex}{ascii}.

Details

The Javascript code for MathJax is contained in this package. If a user viewing a help page has mathjaxr installed, it will be retrieved from there, otherwise it will be retrieved from the CDN site https://cdn.jsdelivr.net/npm/[email protected]/es5/tex-chtml-full.js. To force use of the CDN site, the user can set the environment variable MATHJAXR_USECDN to any non-blank value (e.g., Sys.setenv(MATHJAXR_USECDN=TRUE)). The URL for a diferent CDN can be specified via the environment variable MATHJAXR_CDN.

Notes/Issues

Example

The probability density function of a normal distribution is given by

where denotes the mean of the distribution and its standard deviation.

Installation

The current official (i.e., CRAN) release can be installed within R with:

install.packages("mathjaxr")

The development version of the package can be installed with:

install.packages("remotes")
remotes::install_github("wviechtb/mathjaxr")

This builds the package from source based on the current version on GitHub. Note that Windows users must have Rtools installed for this to work.

Meta

The mathjaxr package is licensed under the GNU General Public License Version 3, while MathJax itself is licensed under the Apache License, Version 2.0. To report any issues or bugs, please go here.