README.md

ggsvg - Use SVG as points in ggplot

R-CMD-check

ggsvg is an extension to ggplot to use SVG images for points.

Variables may be aesthetically mapped to features within the SVG using CSS selectors via the css() helper function.

What’s in the box

Installation

Install from GitHub.

The {rsvg} package is used to convert SVG into an R raster object. This requires at least rsvg(>= 2.3.0).

# install.package('remotes')
install.packages('rsvg')
remotes::install_github('coolbutuseless/ggsvg')

Simple plot

svg_url <- 'https://www.svgrepo.com/download/289000/jellyfish.svg'
svg_txt <- paste(readLines(svg_url), collapse = "\n")
grid::grid.draw( svg_to_rasterGrob(svg_txt) )

test_df <- data.frame(
  x = runif(10), 
  y = runif(10), 
  count = sample(3:5, 10, T),
  type  = sample(c('a', 'b', 'c'), 10, T))

test_df
#>             x         y count type
#> 1  0.26550866 0.2059746     3    b
#> 2  0.37212390 0.1765568     5    b
#> 3  0.57285336 0.6870228     3    a
#> 4  0.90820779 0.3841037     3    c
#> 5  0.20168193 0.7698414     3    a
#> 6  0.89838968 0.4976992     3    c
#> 7  0.94467527 0.7176185     4    b
#> 8  0.66079779 0.9919061     3    b
#> 9  0.62911404 0.3800352     3    b
#> 10 0.06178627 0.7774452     4    b

ggplot(test_df) + 
  geom_point_svg(aes(x, y), svg = svg_txt) + 
  theme_bw()

Simple plot with mapped size aesthetic

ggplot(test_df) + 
  geom_point_svg(aes(x, y, size = type), svg = svg_txt) + 
  theme_bw()

Mapping Aesthetics to SVG features with CSS Selectors

Aesthetic values are mapped to SVG features with CSS Selectors.

Snowman SVG

Here is a simple SVG consisting of 2 stacked circles - a big circle on the bottom and a small circle resting on top.

snowman_txt <- '
  <svg viewBox="0 0 100 100 ">
    <circle id="top" cx="50" cy="20" r="20" fill="brown" stroke="black" />
    <circle id="bot" cx="50" cy="70" r="30" fill="brown" stroke="black" />
  </svg>
  '

grid::grid.draw( svg_to_rasterGrob(snowman_txt, width=800, height=800) )

css() helper function

Use the css() helper function to target aesthetics at selected elements within and SVG using css(selector, property = value)

E.g.

Example

In the following example, two css() selectors are used within the geom_point_svg() call:

To configure how the variable is mapped to the property on the selected target, you can either use:

snowman_txt <- '
  <svg viewBox="0 0 100 100 ">
    <circle id="top" cx="50" cy="20" r="20" fill="brown" stroke="black" />
    <circle id="bot" cx="50" cy="70" r="30" fill="brown" stroke="black" />
  </svg>
  '


ggplot(test_df) + 
  geom_point_svg(
    aes(x, y, css("circle#top", fill = type)),
    css("circle#bot", stroke = 'brown'),
    css("circle", 'stroke-width'=10),
    svg = snowman_txt
  ) +
  theme_bw() + 
  scale_svg_fill_brewer(aesthetics = css("circle#top", fill = type), palette = 'Dark2')

Acknowledgements



coolbutuseless/ggsvg documentation built on Sept. 14, 2024, 5:48 p.m.