Changing Glyph in legend in ggplot2
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 is all the available draw_key_* functions in ggplot2. Notice that the dark gray color in dotplot and polygon is a result of a 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 return 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$linetype %||% 1))
## }
## <bytecode: 0x7ff0874a8c08>
## <environment: namespace:ggplot2>will I try to make a glyph by myself using both points and lines.
library(grid)
library(rlang)
draw_key_smile <- function(data, params, size) {
grobTree(
pointsGrob(0.25, 0.75, size = unit(.25, "npc"), pch = 16),
pointsGrob(0.75, 0.75, size = unit(.25, "npc"), pch = 16),
linesGrob(c(0.9, 0.87, 0.78, 0.65, 0.5, 0.35, 0.22, 0.13, 0.1),
c(0.5, 0.35, 0.22, 0.13, 0.1, 0.13, 0.22, 0.35, 0.5)),
gp = gpar(
col = data$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 3.6.0 (2019-04-26)
os macOS Mojave 10.14.6
system x86_64, darwin15.6.0
ui X11
language (EN)
collate en_US.UTF-8
ctype en_US.UTF-8
tz America/Los_Angeles
date 2020-04-23
─ Packages ───────────────────────────────────────────────────────────────────
! package * version date lib source
P assertthat 0.2.1 2019-03-21 [?] CRAN (R 3.6.0)
P backports 1.1.6 2020-04-05 [?] CRAN (R 3.6.0)
P blogdown 0.18 2020-03-04 [?] CRAN (R 3.6.0)
P bookdown 0.18 2020-03-05 [?] CRAN (R 3.6.0)
P cli 2.0.2 2020-02-28 [?] CRAN (R 3.6.0)
P clipr 0.7.0 2019-07-23 [?] CRAN (R 3.6.0)
P colorspace 1.4-1 2019-03-18 [?] CRAN (R 3.6.0)
P crayon 1.3.4 2017-09-16 [?] CRAN (R 3.6.0)
P desc 1.2.0 2018-05-01 [?] CRAN (R 3.6.0)
P details * 0.2.1 2020-01-12 [?] CRAN (R 3.6.0)
P digest 0.6.25 2020-02-23 [?] CRAN (R 3.6.0)
P dplyr * 0.8.5 2020-03-07 [?] CRAN (R 3.6.0)
P ellipsis 0.3.0 2019-09-20 [?] CRAN (R 3.6.0)
P evaluate 0.14 2019-05-28 [?] CRAN (R 3.6.0)
P fansi 0.4.1 2020-01-08 [?] CRAN (R 3.6.0)
P ggplot2 * 3.3.0 2020-03-05 [?] CRAN (R 3.6.0)
P glue 1.4.0 2020-04-03 [?] CRAN (R 3.6.0)
P gtable 0.3.0 2019-03-25 [?] CRAN (R 3.6.0)
P htmltools 0.4.0 2019-10-04 [?] CRAN (R 3.6.0)
P httr 1.4.1 2019-08-05 [?] CRAN (R 3.6.0)
P knitr * 1.28 2020-02-06 [?] CRAN (R 3.6.0)
P lifecycle 0.2.0 2020-03-06 [?] CRAN (R 3.6.0)
P magrittr * 1.5 2014-11-22 [?] CRAN (R 3.6.0)
P munsell 0.5.0 2018-06-12 [?] CRAN (R 3.6.0)
P pillar 1.4.3 2019-12-20 [?] CRAN (R 3.6.0)
P pkgconfig 2.0.3 2019-09-22 [?] CRAN (R 3.6.0)
P png 0.1-7 2013-12-03 [?] CRAN (R 3.6.0)
P purrr 0.3.3 2019-10-18 [?] CRAN (R 3.6.0)
P R6 2.4.1 2019-11-12 [?] CRAN (R 3.6.0)
P Rcpp 1.0.4.6 2020-04-09 [?] CRAN (R 3.6.0)
renv 0.9.3 2020-02-10 [1] CRAN (R 3.6.0)
P rlang * 0.4.5 2020-03-01 [?] CRAN (R 3.6.0)
P rmarkdown 2.1 2020-01-20 [?] CRAN (R 3.6.0)
P rprojroot 1.3-2 2018-01-03 [?] CRAN (R 3.6.0)
P rstudioapi 0.11 2020-02-07 [?] CRAN (R 3.6.0)
P scales 1.1.0 2019-11-18 [?] CRAN (R 3.6.0)
P sessioninfo 1.1.1 2018-11-05 [?] CRAN (R 3.6.0)
P stringi 1.4.6 2020-02-17 [?] CRAN (R 3.6.0)
P stringr 1.4.0 2019-02-10 [?] CRAN (R 3.6.0)
P tibble 3.0.1 2020-04-20 [?] CRAN (R 3.6.2)
P tidyselect 1.0.0 2020-01-27 [?] CRAN (R 3.6.0)
P vctrs 0.2.4 2020-03-10 [?] CRAN (R 3.6.0)
P withr 2.1.2 2018-03-15 [?] CRAN (R 3.6.0)
P xfun 0.13 2020-04-13 [?] CRAN (R 3.6.2)
P xml2 1.3.0 2020-04-01 [?] CRAN (R 3.6.2)
P yaml 2.2.1 2020-02-01 [?] CRAN (R 3.6.0)
[1] /Users/emilhvitfeldthansen/Desktop/blogv4/renv/library/R-3.6/x86_64-apple-darwin15.6.0
[2] /private/var/folders/m0/zmxymdmd7ps0q_tbhx0d_26w0000gn/T/Rtmpw7nrsD/renv-system-library
P ── Loaded and on-disk path mismatch.
