otexts

Shared R setup for the OTexts books written with Quarto, such as Forecasting: Principles and Practice and That's Weird!. It is the R companion to the otexts Quarto format, which sets the books' HTML styling and figure sizes.

Installation

# install.packages("pak")
pak::pak("OTexts/otexts")

Usage

Each chapter of a book sources a setup script, before-each-chapter.R, which calls setup_book():

library(otexts)
setup_book()

This

• registers a "BookMath" font family for maths in plot labels;
• sets printing options, and the Okabe-Ito and viridis palettes as ggplot2's default colour scales;
• sets the ggplot2 theme, so plot text is in the book's font;
• prefers dplyr::select() and dplyr::filter() when conflicted is installed;
• defines TeX() as tex() and theme_void() as theme_book_void(), so the code shown in the book runs unchanged for readers, using latex2exp::TeX() and ggplot2::theme_void().

tex() sets the maths in plot labels in the same fonts that KaTeX uses for maths in the text:

library(ggplot2)
ggplot(mtcars, aes(wt, mpg)) +
  geom_point() +
  labs(x = TeX("Weight ($w$)"), y = TeX("$\\hat{y}_i$"))

After each render, post_render() tidies the HTML with the otexts Quarto format's htmlreplace.pl and compresses the figures with pngquant, which must be installed. A book runs it from post-render.R, set with project: post-render in _quarto.yml:

otexts::post_render()

Other helpers: cache() saves long computations in rds/, and html_math() marks up maths in raw HTML for KaTeX.

A translation in a script that Fira Sans doesn't cover can use another installed font for plot text, e.g. setup_book(text_font = "Noto Sans CJK SC").

Fonts

Plot text is in Fira Sans, which must be installed. The fonts in inst/fonts/ are copies of KaTeX's maths fonts (MIT licence), scaled up by 1.2 to match Fira Sans by data-raw/make_plot_fonts.py.