Ggplot2 gradient tests

ggplot2-gradient-tests.r

library(tidyverse)

my_gradient <- grid::linearGradient(
  colours = c("#020024", "#102b81", "#833ab4"),
  stops = c(0, 0.4, 1))

# works!

myplot <-
  ggplot(mtcars) +
  aes(mpg, hp, size = disp) +
  geom_point() +
  theme_grey(base_size = 20) +
  theme(
    legend.background = element_rect(
      fill = my_gradient)) +
  labs(title = "Hello gradients!", subtitle = "Another go")

ggsave('test_grad_legend.png', myplot, device = png(type = "cairo-png"))

# nope

myplot <-
  ggplot(mtcars %>% rownames_to_column()) +
  aes(x = rowname, y = mpg) +
  geom_col(fill = my_gradient) +
  theme_grey(base_size = 20) +
  labs(title = "Hello gradients!", subtitle = "Another go")

ggsave('test_grad_bars.png', myplot, device = png(type = "cairo-png"))

# also nope: passing a list of gradient objects for each geom element

myplot <-
  ggplot(mtcars %>% rownames_to_column()) +
  aes(x = rowname, y = mpg) +
  geom_col(fill = map(1:nrow(mtcars), ~ my_gradient)) +
  theme_grey(base_size = 20) +
  labs(title = "Hello gradients!", subtitle = "Another go")

ggsave('test_grad_bars.png', myplot, device = png(type = "cairo-png"))