How could I align two ggpubr histograms so they are facing each other?-CodePudding

I am trying to align two histograms so they face each other, like the image of this link: [Example image] (https://i.stack.imgur.com/mI6Q4.png)

I had the two individual histograms for each group, and I tried to align them using the function align_plots from cowplot. However, I end with something like this: ![My aligned plots] (https://i.stack.imgur.com/E04UQ.png)

Here is the code I used to align them, and regarding any changes in the align and axis parameters, the image still result in something similar to the second one posted above:

aligned_hist <- cowplot::align_plots(Asyhist, Symhist, align = "hv", axis = "b")
align_hist <- ggdraw(aligned_hist[[1]])   draw_plot(aligned_hist[[2]])
align_hist

Sorry for not posting the images directly, but I am new in stack overflow and didn't allow me to do it. Hope somebody could help me to figure this out. Thanks!

CodePudding user response：

I don't know about ggpubr histograms, but an approach with vanilla ggplot2 would be to use after_stat() to change the value depending on the group.

library(ggplot2)

set.seed(0)
df <- data.frame(
  x = c(rnorm(100, 1), rnorm(100, 2)),
  group = rep(c("A", "B"), each = 100)
)

ggplot(df, aes(x, fill = group))  
  geom_histogram(
    aes(y = after_stat(ifelse(group == 2, -1, 1) * count))
  )  
  scale_y_continuous(labels = abs)
#> `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

^{Created on 2021-09-11 by the reprex package (v2.0.1)}