I want to draw two histogram on same plot window but placed vertically. One such example can be found at https://blogs.sas.com/content/graphicallyspeaking/files/2013/11/MirrorHistogramVert.png
Below is my code
library(ggplot2)
set.seed(1)
dat = rbind(data.frame('val' = rnorm(100), 'met' = 'Metric1'), data.frame('val' = rt(100, 2), 'met' = 'Metric12'))
ggplot(dat, aes(x = val, y = met, color = met)) + geom_histogram()
However I am getting below error
Error in `geom_histogram()`:
! Problem while computing stat.
ℹ Error occurred in the 1st layer.
Caused by error in `setup_params()`:
! `stat_bin()` must only have an x or y aesthetic.
Run `rlang::last_trace()` to see where the error occurred.
I also want to add probability curve for Normal distribution for both histogram.
Any suggestion what could be the right approach will be very helpful
1
You could do two separate layers for the two groups, using y = -after_stat(count) in the second layer (the default for geom_histogram is y = after_stat(count).
Ensure the breaks for both layers are the same so that the bins line up.
ggplot(dat, aes(x = val, fill = met)) +
geom_histogram(data = dat[dat$met == 'Metric1',],
breaks = seq(-40, 10, 0.5),
colour = "black",
alpha = 0.3) +
geom_histogram(data = dat[dat$met == 'Metric12', ],
breaks = seq(-40, 10, 0.5),
mapping = aes(y = -after_stat(count)),
colour = "black",
alpha = 0.3) +
scale_fill_manual(values = c('blue3', 'red3')) +
coord_cartesian(xlim = c(-10, 10)) +
labs(y = 'count') +
theme_bw(20) +
theme(panel.border = element_blank())
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