How to add a line in boxplot?

Question

I would like to add lines between \"mean\" in my boxplot.

My code:

library(ggplot2)
library(ggthemes)

Gp=factor(c(rep(\"G1\",80),rep(\"G2\",80)))
Fc=fac         


        

Answer 1

Here's an alternative:

DATA$U <- paste(X, Z) # Extra interaction
qplot(U, Y, data = DATA, geom = "boxplot", fill = Z, na.rm = TRUE, 
      outlier.size = NA, outlier.colour = NA) +
  facet_grid(Gp ~ Fc) + theme_light() + scale_colour_gdocs() +
  theme(legend.position = "bottom") + 
  stat_summary(fun.y = mean, geom = "point", shape = 23, position = position_dodge(width = .75)) +
  stat_summary(fun.y = mean, geom = "line", aes(group = X)) + # Lines
  scale_x_discrete(labels = rep(levels(X), each = 2)) + xlab("X") # Some fixes