如何在ggplot2 geom_jitter（）中更改数据点的颜色范围

Question

I am having fun exploring R and ggplot2. I am now having a problem to change the gradient of my data points when using ggplot2 and geom_jitter. Here is the code I am using:

t1 <- ggplot(mtcars, aes(x=as.factor(cyl),y=mpg))
t2 <- geom_boxplot(outlier.shape=NA)
t3 <- geom_jitter(width=0.3, size=3, aes(color = disp))
t1 + t2 + t3

returns:

However, I would like the higher number to be dark. Or even better - I would like to have the highest numbers in red and the lowest numbers in green (just an example).

Thanks!

Answer 1

This works :

t1 <- ggplot(mtcars, aes(x=as.factor(cyl),y=mpg))
t2 <- geom_boxplot(outlier.shape=NA)
t3 <- geom_jitter(width=0.3, size=3, aes(color = disp))
t4 <- scale_colour_gradient(low="green",high="red") 
t1 + t2 + t3 + t4

Answer 2

您需要将disp定义为表明变量顺序的分类变量

mtcars$disp = factor(mtcars$disp, levels = names_of_levels_ordered)