Coloring Histograms in R-CodePudding

I am trying to plot the following data:

library(ggplot2)

my_data <- data.frame( a = abs(rnorm(1000,17,10)),
b = a)

my_data$col = as.factor(ifelse(my_data$a > 17, "red", "blue"))

ggplot(my_data, aes(x=a))   
  geom_histogram(binwidth=1)

But for some reason, when I try to add colors, I get the following error:

ggplot(my_data, aes(x=a))   
  geom_histogram(binwidth=1, color = my_data$col)

Error: Aesthetics must be either length 1 or the same as the data (59): colour

Can someone please show me how to fix this error?

Thanks

CodePudding user response：

You may use cut with scale_fill_manual.

library(ggplot2)

my_data <- data.frame(a = abs(rnorm(1000,17,10)))
my_data$col = cut(my_data$a, c(-Inf, 17, Inf))

ggplot(my_data, aes(x=a, fill = col))   
  geom_histogram(binwidth=1)   
  scale_fill_manual(breaks = levels(my_data$col), values = c('blue', 'red'))