Getting an error that ggplot2_3.2.0 can't draw more than one boxplot per group

Question

I have xy data that I'd like to plot using R's ggplot:

library(dplyr)
library(ggplot2)
set.seed(1)

df <- data.frame(group = unlist(lapply(LETTERS[1:5],function(l) rep(l,5))),
                 x = rep(1:5,5),
                 y = rnorm(25,2,1),
                 y.se = runif(25,0,0.1)) %>%
  dplyr::mutate(y.min = y-3*y.se,
                y.low = y-y.se,
                y.high = y+y.se,
                y.max = y+3*y.se)

As you can see, while df$x is a point (integer), df$y has an associated error, which I would like to include using a box plot.

So my purpose is to plot each row in df by its x coordinate, using y.min, y.low, y, y.high, and y.max to construct a boxplot, and color and fill it by group. That means, that I'd like to have each row in df, plotted as a box along a separate x-axis location and faceted by df$group, such that df$group A's five replicates appear first, then to their right df$group B's replicates, and so on.

This code used to work for my purpose until I just installed the latest ggplot2 package (ggplot2_3.2.0):

ggplot(df,aes(x=x,ymin=y.min,lower=y.low,middle=y,upper=y.high,ymax=y.max,col=group,fill=group))+
geom_boxplot(position=position_dodge(width=0),alpha=0.5,stat="identity")+
facet_grid(~group,scales="free_x")+scale_x_continuous(breaks = integerBreaks())

Now I'm getting this error:

Error: Can't draw more than one boxplot per group. Did you forget aes(group = ...)?

Any idea?

Answer 1

You need a separate boxplot for each combination of x and group, so you can set the group aesthetic to interaction(x, group):

ggplot(df,aes(x=x,ymin=y.min,lower=y.low,middle=y,upper=y.high,
              ymax=y.max,col=group,fill=group))+
    geom_boxplot(aes(group = interaction(x, group)), 
                 position=position_dodge(width=0),
                 alpha=0.5,stat="identity")