Skip to contents

easeling

A small graphics device that writes R plots directly as OOXML DrawingML shapes, for use with openxlsx2::wb_add_drawing(). No Cairo, FreeType, fontconfig, or xml2 dependency.

Install

You can install development versions via r-universe:

install.packages(
  "easeling",
  repos = c("https://janmarvin.r-universe.dev", "https://cloud.r-project.org")
)

Or from GitHub directly:

# install.packages("remotes")
remotes::install_github("JanMarvin/easeling")

Usage

easel_dev() opens the device and returns a file path. Draw with any R plotting system, call dev.off(), then hand the file to openxlsx2::wb_add_drawing().

library(easeling)
library(openxlsx2)

f <- easel_dev(width = 6, height = 4)
plot(1:10, (1:10)^2, type = "b")
dev.off()

wb <- wb_workbook()$add_worksheet()$add_drawing(xml = f, dims = "A1")

tinyplot 

library(tinyplot)

f <- easel_dev(width = 6, height = 4)
plt(mpg ~ wt | factor(cyl), data = mtcars)
dev.off()

wb$add_worksheet()$add_drawing(xml = f, dims = "A1")

ggplot2 

library(ggplot2)

f <- easel_dev(width = 6, height = 4)
print(
  ggplot(mtcars, aes(wt, mpg, color = factor(cyl))) +
    geom_point() +
    theme_minimal()
)
dev.off()

wb$add_worksheet()$add_drawing(xml = f, dims = "A1")

if (interactive()) wb$open()

Notes

  • Text metrics come from systemfonts when it is installed, otherwise from a built-in table. Legend spacing and centred labels can be a little off with the built-in table; metrics = in ?easel_dev takes your own numbers instead.
  • The machine writing a drawing need not have the font it will be opened with, and systemfonts substitutes without saying so. Some substitutes exist to match (Carlito for Calibri, Liberation Sans for Arial), others are unrelated fonts of quite different width. font_match() reports which font was measured.
  • Fonts are referenced by name only, not embedded. The viewer needs the font installed, or it falls back silently.
  • A few packages draw part of a plot as a string and assume how wide it will come out. tinyplot’s gradient legend draws each tick as the literal "- -", right-aligned to the colour bar, which only lines up where two hyphens and three spaces are wider than the bar. They are under pdf(), which is what the string was written against, but not under Calibri, where the dashes end up about 2.5 pt inside the bar, and not under the cairo devices either. Nothing on the easeling side changes that; a wider font such as DejaVu Sans avoids it.
  • Gradient fills (grid::linearGradient()/radialGradient()) are supported; tiling patterns and clip paths/masks are not.