steveharoz/ggtextures

Drawing textured rectangles and bars with ggplot

ggtextures

Written by Claus O. Wilke

This package provides functions to draw textured rectangles and bars with the grid graphics system and with ggplot2.

Note: The package is at the stage of tech demo/proof of concept. It is not ready for production purposes.

Installation

Please install from github via:

devtools::install_github("clauswilke/ggtextures")

Example

Basic example of a textured rectangle drawn with grid:

library(ggtextures)
library(grid)
library(magick)
#> Linking to ImageMagick 6.9.9.39
#> Enabled features: cairo, fontconfig, freetype, lcms, pango, rsvg, webp
#> Disabled features: fftw, ghostscript, x11

img <- image_read("https://jeroen.github.io/images/Rlogo.png")

grid.newpage()
tg1 <- texture_grob(
  img,
  x = unit(.2, "npc"), y = unit(.05, "npc"),
  width = unit(.1, "npc"), height = unit(.9, "npc"),
  img_width = unit(.5, "in"), ncol = 1
)
tg2 <- texture_grob(
  img,
  x = unit(.5, "npc"), y = unit(.05, "npc"),
  width = unit(.3, "npc"), height = unit(.6, "npc"),
  img_width = unit(.5, "in"), ncol = 1
)

grid.draw(tg1)
grid.draw(tg2)

This is a basic example of textured rectangles in ggplot2:

library(ggplot2)
library(tibble)

data <- tibble(
  xmin = c(1, 2.5), ymin = c(1, 1), xmax = c(2, 4), ymax = c(4, 3),
  image = list(
    "https://jeroen.github.io/images/Rlogo.png",
    image_read_svg("https://jeroen.github.io/images/tiger.svg")
  )
)

ggplot(data, aes(xmin = xmin, xmax = xmax, ymin = ymin, ymax = ymax, image = image)) +
  geom_textured_rect(img_width = unit(1, "in"))

Note that we are reading in the svg file explicitly, using the function `image_read_svg()` from the magick package. This is needed for proper handling of transparencies in svg files.

We can also make a textured equivalent to geom_col() or geom_bar():

df <- tibble(
  trt = c("a", "b", "c"),
  outcome = c(2.3, 1.9, 3.2),
  image = c(
    "http://www.hypergridbusiness.com/wp-content/uploads/2012/12/rocks2-256.jpg",
    "http://www.hypergridbusiness.com/wp-content/uploads/2012/12/stone2-256.jpg",
    "http://www.hypergridbusiness.com/wp-content/uploads/2012/12/siding1-256.jpg"
  )
)

ggplot(df, aes(trt, outcome, image = image)) +
  geom_textured_col(img_width = unit(0.5, "null"))

images = c(
  compact = "http://www.hypergridbusiness.com/wp-content/uploads/2012/12/rocks2-256.jpg",
  midsize = "http://www.hypergridbusiness.com/wp-content/uploads/2012/12/stone2-256.jpg",
  suv = "http://www.hypergridbusiness.com/wp-content/uploads/2012/12/siding1-256.jpg",
  `2seater` = "http://www.hypergridbusiness.com/wp-content/uploads/2012/12/mulch1-256.jpg",
  minivan = "http://www.hypergridbusiness.com/wp-content/uploads/2012/12/rocks1-256.jpg",
  pickup = "http://www.hypergridbusiness.com/wp-content/uploads/2012/12/wood3-256.jpg",
  subcompact = "http://www.hypergridbusiness.com/wp-content/uploads/2012/12/concrete1-256.jpg"
)

ggplot(mpg, aes(class, image = class)) +
  geom_textured_bar() +
  scale_image_manual(values = images)

ggplot(mpg, aes(factor(trans), image = class)) +
  geom_textured_bar() +
  scale_image_manual(values = images)

Isotype bars can be drawn with geom_isotype_bar() and geom_isotype_col(). The units of the images are set as grid native units. Default is that the image height corresponds to one data unit.

data <- tibble(
  count = c(5, 3, 6),
  animal = c("giraffe", "elephant", "horse"),
  image = list(
    image_read_svg("http://steveharoz.com/research/isotype/icons/giraffe.svg"),
    image_read_svg("http://steveharoz.com/research/isotype/icons/elephant.svg"),
    image_read_svg("http://steveharoz.com/research/isotype/icons/horse.svg")
  )
)

ggplot(data, aes(animal, count, image = image)) +
  geom_isotype_col() +
  theme_minimal()

ggplot(data, aes(animal, count, image = image)) +
  geom_isotype_col(
    img_width = grid::unit(1, "native"), img_height = NULL,
    ncol = NA, nrow = 1, hjust = 0, vjust = 0.5, fill = "#80808040"
  ) +
  coord_flip() +
  theme_minimal()