CODEWITHSUNDEEP
rplotggplot2boxplot
coanil
coanil

Reputation: 272

Dodging boxplots and error bars with ggplot2

library(ggplot2)
library(Hmisc)
data(mtcars)
myplot <- ggplot(mtcars, aes(x = as.factor(cyl), y = qsec)) +
    geom_boxplot() +
    stat_summary(fun.y = mean, geom = "point", shape = 5, size = 2) +
    stat_summary(fun.data = mean_cl_normal, geom = "errorbar",
             width = 0.2)

produces plot

I'd like to dodge the mean and error bars a bit to the right, such that the error bars don't obscure the IQR line of the boxplot. Specifying position=position_dodge(.5) doesn't seem to work, because geom_errorbardoesn't know about geom_boxplot.

Upvotes: 0

Views: 2132

Answers (1)

thothal
thothal

Reputation: 20379

You can introduce a new variable which you use as the x offset for your errorbars:

library(ggplot2)
library(Hmisc)
data(mtcars)
mtcars$cyl.n <- as.numeric(as.factor(mtcars$cyl)) + .5

(myplot <- ggplot(mtcars, aes(x = as.factor(cyl), y = qsec)) +
    geom_boxplot() +
    stat_summary(aes(x = cyl.n), fun.y = mean, geom = "point", shape = 5, size = 2) +
    stat_summary(aes(x = cyl.n), fun.data = mean_cl_normal, geom = "errorbar",
           width = 0.2))

enter image description here

The as.numeric(as.factor(.)) makes sure that the new error bar is spaced at the same position as the boxplots but shifted by 0.5 units.

Upvotes: 1

Related Questions