如何为我的ggplot指定颜色？

Question

我是使用ggplot的新手。我想要为组指定我想要的颜色（即High = red4; Low = gray45）。组由＆＃34; high＆＃34;定义。或＆＃34;低＆＃34;值。

ggplot(my_data, aes(x=continuous_variable, fill=Group)) + geom_histogram() + 
  xlab("continuous_variable")+ 
  ylab("Frequency") + 
  ggtitle("My Variable")

Answer 1

Axeman指出你已经朝着正确的方向前进了：只需在代码中添加scale_fill_manual。

可重复的例子：

library(ggplot2)

# sample data
set.seed(1234)
continuous_variable <- rnorm(100)
Group <- factor(rep(c("high", "low"), 50))
my_data <- data.frame(continuous_variable, Group)

# just add another line to your initial code
ggplot(my_data, aes(x = continuous_variable, fill = Group)) + geom_histogram() + 
  xlab("continuous_variable") + 
  ylab("Frequency") + 
  ggtitle("My Variable") + 
  scale_fill_manual(values = c("high" = "red4", "low" = "grey45"))
#> stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.