linewidth

ggplot2 3.4.0

ggplot2

ggplot2 3.4.0 introduces a new linewidth aesthetic.

Published

November 4, 2022

Install ggplot2 3.4.0 with:

pak::pak("cran/ggplot2@3.4.0")

linewidth

linewidth will take over sizing of the width of lines - something that was handled previously by size.

Before
After

library(ggplot2, lib.loc = new_lib)

ggplot(airquality) +
  geom_line(aes(Day, Temp, size = Month, group = Month)) +
  scale_size(range = c(0.5, 3))

library(ggplot2)

ggplot(airquality) + 
  geom_line(aes(Day, Temp, linewidth = Month, group = Month)) + 
  scale_linewidth(range = c(0.5, 3))

You will get a deprecation message if you try to use size when you should be using linewidth.

ggplot(airquality) + 
  geom_line(aes(Day, Temp, size = Month, group = Month)) + 
  scale_size(range = c(0.5, 3))

Warning: Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
ℹ Please use `linewidth` instead.

When size is a valid aesthetic like geom_sf() or geom_pointrange(), you will not get a deprecation warning.

ggplot(airquality) +
  geom_pointrange(aes(x = factor(Month), y = Temp), stat = "summary", size = 2)

No summary function supplied, defaulting to `mean_se()`

On the point of geom_sf(), the default line width is now 0.2 instead of 0.5:

library(sf)
library(patchwork)
tn <- leaidr::lea_get("tn")

OGR data source with driver: ESRI Shapefile 
Source: "/private/var/folders/pj/nmg9b8_93dq4kwt8nt2d4cj40000gn/T/RtmphQMPaE/47", layer: "47"
with 158 features
It has 18 fields

p1 <- tn %>% 
  sf::st_as_sf() %>% 
  ggplot() +
  geom_sf(linewidth = 0.5) + 
  ggtitle("Old default")

p2 <- tn %>% 
  sf::st_as_sf() %>% 
  ggplot() +
  geom_sf(linewidth = 0.2) + 
  ggtitle("New default")

p1/p2

The switch to linewidth goes beyond aesthetics and targets everything that used size to target line width.

linewidth

Learn more