Ggplot2：添加更多特定 colored颜色的线条

发布于01月22日

我正试图在我的折线图中添加更多的线条.如何确保所有新添加的行都呈灰色显示？

first4letters <- c(rep("A", 3), rep("B", 3), rep("C", 3), rep("D", 3))
times <- rep(c("time1", "time2", "time3"), 4)
score <- c(5, 10, 2, 3, 4, 7, 11, 2, 9, 4, 6, 11)

df <- data.frame(first4letters, times, score)
df

plot1 <- ggplot(data = df, aes(times, score, group = first4letters)) + 
  geom_line(aes(color = first4letters)) +
  geom_point(aes(color = factor(first4letters)), size = 1) +
  theme_classic()
plot1 + scale_color_manual(values = c("red", "blue", "black", "orange"))

我会添加一些新的字母.但是，显示这些字母的线条必须是灰色的.我不能向scale_color_manual()函数添加新值.因为该函数本身决定了 colored颜色的顺序.

推荐答案

一种 Select 是使用命名的 colored颜色向量.这样做，所有其他类别将自动分配na.value=:

在示例数据中再添加两个字母:

library(ggplot2)

first4letters <- c(
  rep("A", 3), rep("B", 3),
  rep("C", 3), rep("D", 3),
  rep("E", 3), rep("F", 3)
)
times <- rep(
  c("time1", "time2", "time3"), 6
)
score <- c(
  5, 10, 2, 3, 4, 7, 11, 2, 9, 4,
  6, 11, 3, 8, 9, 10, 12, 3
)

df <- data.frame(first4letters, times, score)

pal_color <- c("red", "blue", "black", "orange")
names(pal_color) <- LETTERS[1:4]

ggplot(data = df, aes(times, score, group = first4letters)) +
  geom_line(aes(color = first4letters)) +
  geom_point(aes(color = factor(first4letters)), size = 1) +
  theme_classic() +
  scale_color_manual(values = pal_color, na.value = "grey80")