library(tidyverse)
delta <- tibble(
type = c("alpha", "beta", "gamma"),
a = rnorm(3, 5),
b = rnorm(3, 6)
) %>%
mutate(delta = abs(a - b)) %>%
gather(`a`, `b`, `delta`, key = "letter", value = "value")
ggplot(delta %>% filter(letter != "delta"), aes(type, value, fill = letter)) +
geom_col(position = "dodge") +
geom_col(data = delta %>% filter(letter == "delta"), width = 0.5) +
scale_color_manual("grey", "black", "blue")
我希望将
a
和 b
条形图变为灰色和黑色。将 delta
条形图变为蓝色。如何使用 scale_color_manual()
实现?似乎我上面的语法有误。