如何在R的单个图中使用多种颜色？

Question

x=rnorm(6000, 10, 4)
 plot(x, type = "l")

对于索引0-2000我想使用green color ，接下来的2000-4000红色和最后的4000-6000 blue color 。

如何用多种颜色为该图着色？

Answer 1

您可以使用lines并指定x位置以不同颜色绘制 x 值：

x=rnorm(6000, 10, 4)
plot(x[1:2000], type = "l", xlim = c(0,6000), col = "green")
lines(x = 2000:4000, y = x[2000:4000], col = "red")
lines(x = 4000:6000, y = x[4000:6000], col = "blue")

Answer 2

这是一个ggplot解决方案：

library(tidyverse)

df <- 
  x %>% 
  enframe(name = "Index") %>% 
  mutate(
    color = case_when(
      Index <= 2000 ~ "green", 
      Index <= 4000 ~ "red",
      TRUE ~ "blue"
    )
  )

df %>% 
  ggplot(aes(x = Index, y = value, color = color)) +
  geom_line(show.legend = FALSE) +
  scale_color_manual(values = c("blue" = "blue", "green" = "green", "red" = "red"))