ggplot2 reorder my boxplot by 80th percentile

Question

I want to reorder my boxplots in order of their 80th percentile values.

my plot looks like this:

my code structure is along the lines of:

ggplot(data, aes(x=reorder(y, x, median), y)) +
  geom_boxplot(fill="deepskyblue") +
  stat_boxplot(geom ='errorbar', width=0.3) + 
  theme_bw()+
  scale_y_continuous(trans="log10", n.breaks = 6)

currently ive ordered them by median. I have two questions:

1. it looks like it orders the boxplots by the median up til about 1/3rd of the plot, then goes back to random ordering. Why would this be?

2. how can i easily order it by the 80th percentile? i tried subbing in quantile(0.8, y) for median but get an error.

i unfortunately can't share the data structure/variables as its confidential.

Thanks.

Answer 1

1. The problem of not having the graph in order may be due to NAs, try filtering them previously:

   data <- data %>% filter(!is.na(y))

2. try FUN = quantile, prob = 0.80, in the reorder function you will end up with:

    ggplot(data, aes(x=reorder(y, x, FUN = quantile, prob=0.80), y)) +
    geom_boxplot(fill="deepskyblue") +
    stat_boxplot(geom ='errorbar', width=0.3) + 
    theme_bw()+
    scale_y_continuous(trans="log10", n.breaks = 6)