Introduction
The newest version of ggplot2 3.2.0 gave us the ability to change the glyph in the legend like so
library(ggplot2)
ggplot(economics_long, aes(date, value01, colour = variable)) +
geom_line(key_glyph = "timeseries")
And they can likewise be specified with the draw_key_* functions as well
ggplot(economics_long, aes(date, value01, colour = variable)) +
geom_line(key_glyph = draw_key_timeseries)
Showcase
The following are all the available draw_key_* functions in ggplot2. Notice that the dark gray color in dot-plot and polygon is a result of an unspecified fill aesthetic. Code to generate these figures can be found at the end of this post.
##
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
##
## filter, lag
## The following objects are masked from 'package:base':
##
## intersect, setdiff, setequal, union
Custom glyph key
Since the draw_key_* function just returns a grob, you can use spend some time and create your own custom glyphs! Taking inspiration from draw_key_boxplot
draw_key_boxplot
## function (data, params, size)
## {
## grobTree(linesGrob(0.5, c(0.1, 0.25)), linesGrob(0.5, c(0.75,
## 0.9)), rectGrob(height = 0.5, width = 0.75), linesGrob(c(0.125,
## 0.875), 0.5), gp = gpar(col = data$colour %||% "grey20",
## fill = alpha(data$fill %||% "white", data$alpha), lwd = (data$size %||%
## 0.5) * .pt, lty = data$linetype %||% 1))
## }
## <bytecode: 0x7fcdd88de808>
## <environment: namespace:ggplot2>will I try to make a glyph by myself using both points and lines.
library(grid)
library(rlang)
draw_key_smile <- function(data, params, size) {
grobTree(
pointsGrob(0.25, 0.75, size = unit(.25, "npc"), pch = 16),
pointsGrob(0.75, 0.75, size = unit(.25, "npc"), pch = 16),
linesGrob(c(0.9, 0.87, 0.78, 0.65, 0.5, 0.35, 0.22, 0.13, 0.1),
c(0.5, 0.35, 0.22, 0.13, 0.1, 0.13, 0.22, 0.35, 0.5)),
gp = gpar(
col = data$colour %||% "grey20",
fill = alpha(data$fill %||% "white", data$alpha),
lwd = (data$size %||% 0.5) * .pt,
lty = data$linetype %||% 1
)
)
}
ggplot(economics_long, aes(date, value01, colour = variable)) +
geom_line(key_glyph = draw_key_smile)
And it looks so happy!
Appendix
library(dplyr)
library(magrittr)
library(ggplot2)
library(grid)
draws <- ls(getNamespace("ggplot2"), pattern = "^draw_key_")
legend_fun <- function(x) {
ggg <- economics_long %>%
mutate(variable = factor(variable, labels = paste("Option", LETTERS[1:5]))) %>%
ggplot(aes(date, value01, colour = variable)) +
geom_line(key_glyph = get(x)) +
labs(color = x)
legend <- cowplot::get_legend(ggg)
grid.newpage()
grid.draw(legend)
}
purrr::walk(draws[1:12], legend_fun)
p <- ggplot(mtcars, aes(wt, mpg, label = rownames(mtcars))) +
geom_text(aes(colour = factor(ceiling(seq_len(nrow(mtcars)) %% 5), labels = paste("Option", LETTERS[1:5])))) +
labs(color = "draw_key_text")
legend <- cowplot::get_legend(p)
grid.newpage()
grid.draw(legend)
purrr::walk(draws[14:16], legend_fun)session information
─ Session info ───────────────────────────────────────────────────────────────
setting value
version R version 4.1.0 (2021-05-18)
os macOS Big Sur 10.16
system x86_64, darwin17.0
ui X11
language (EN)
collate en_US.UTF-8
ctype en_US.UTF-8
tz America/Los_Angeles
date 2021-07-15
─ Packages ───────────────────────────────────────────────────────────────────
package * version date lib source
assertthat 0.2.1 2019-03-21 [1] CRAN (R 4.1.0)
blogdown 1.3.2 2021-06-09 [1] Github (rstudio/blogdown@00a2090)
bookdown 0.22 2021-04-22 [1] CRAN (R 4.1.0)
bslib 0.2.5.1 2021-05-18 [1] CRAN (R 4.1.0)
cli 3.0.0 2021-06-30 [1] CRAN (R 4.1.0)
clipr 0.7.1 2020-10-08 [1] CRAN (R 4.1.0)
codetools 0.2-18 2020-11-04 [1] CRAN (R 4.1.0)
colorspace 2.0-2 2021-06-24 [1] CRAN (R 4.1.0)
cowplot 1.1.1 2020-12-30 [1] CRAN (R 4.1.0)
crayon 1.4.1 2021-02-08 [1] CRAN (R 4.1.0)
DBI 1.1.1 2021-01-15 [1] CRAN (R 4.1.0)
desc 1.3.0 2021-03-05 [1] CRAN (R 4.1.0)
details * 0.2.1 2020-01-12 [1] CRAN (R 4.1.0)
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dplyr * 1.0.7 2021-06-18 [1] CRAN (R 4.1.0)
ellipsis 0.3.2 2021-04-29 [1] CRAN (R 4.1.0)
evaluate 0.14 2019-05-28 [1] CRAN (R 4.1.0)
fansi 0.5.0 2021-05-25 [1] CRAN (R 4.1.0)
farver 2.1.0 2021-02-28 [1] CRAN (R 4.1.0)
generics 0.1.0 2020-10-31 [1] CRAN (R 4.1.0)
ggplot2 * 3.3.5 2021-06-25 [1] CRAN (R 4.1.0)
glue 1.4.2 2020-08-27 [1] CRAN (R 4.1.0)
gtable 0.3.0 2019-03-25 [1] CRAN (R 4.1.0)
highr 0.9 2021-04-16 [1] CRAN (R 4.1.0)
htmltools 0.5.1.1 2021-01-22 [1] CRAN (R 4.1.0)
httr 1.4.2 2020-07-20 [1] CRAN (R 4.1.0)
jquerylib 0.1.4 2021-04-26 [1] CRAN (R 4.1.0)
jsonlite 1.7.2 2020-12-09 [1] CRAN (R 4.1.0)
knitr * 1.33 2021-04-24 [1] CRAN (R 4.1.0)
labeling 0.4.2 2020-10-20 [1] CRAN (R 4.1.0)
lifecycle 1.0.0 2021-02-15 [1] CRAN (R 4.1.0)
magrittr * 2.0.1 2020-11-17 [1] CRAN (R 4.1.0)
munsell 0.5.0 2018-06-12 [1] CRAN (R 4.1.0)
pillar 1.6.1 2021-05-16 [1] CRAN (R 4.1.0)
pkgconfig 2.0.3 2019-09-22 [1] CRAN (R 4.1.0)
png 0.1-7 2013-12-03 [1] CRAN (R 4.1.0)
purrr 0.3.4 2020-04-17 [1] CRAN (R 4.1.0)
R6 2.5.0 2020-10-28 [1] CRAN (R 4.1.0)
rlang * 0.4.11 2021-04-30 [1] CRAN (R 4.1.0)
rmarkdown 2.9 2021-06-15 [1] CRAN (R 4.1.0)
rprojroot 2.0.2 2020-11-15 [1] CRAN (R 4.1.0)
sass 0.4.0 2021-05-12 [1] CRAN (R 4.1.0)
scales 1.1.1 2020-05-11 [1] CRAN (R 4.1.0)
sessioninfo 1.1.1 2018-11-05 [1] CRAN (R 4.1.0)
stringi 1.6.2 2021-05-17 [1] CRAN (R 4.1.0)
stringr 1.4.0 2019-02-10 [1] CRAN (R 4.1.0)
tibble 3.1.2 2021-05-16 [1] CRAN (R 4.1.0)
tidyselect 1.1.1 2021-04-30 [1] CRAN (R 4.1.0)
utf8 1.2.1 2021-03-12 [1] CRAN (R 4.1.0)
vctrs 0.3.8 2021-04-29 [1] CRAN (R 4.1.0)
withr 2.4.2 2021-04-18 [1] CRAN (R 4.1.0)
xfun 0.24 2021-06-15 [1] CRAN (R 4.1.0)
xml2 1.3.2 2020-04-23 [1] CRAN (R 4.1.0)
yaml 2.2.1 2020-02-01 [1] CRAN (R 4.1.0)
[1] /Library/Frameworks/R.framework/Versions/4.1/Resources/library