Pairing samples with violin plot in R

Question

I'm trying to reproduce this graph from ggpaired (ggpubr) but with violin plot instead of boxplot:

before <-c(200.1, 190.9, 192.7, 213, 241.4, 196.9, 172.2, 185.5, 205.2, 193.7)
after <-c(392.9, 393.2, 345.1, 393, 434, 427.9, 422, 383.9, 392.3, 352.2)

 d <- data.frame(before = before, after = after)
 ggpaired(d, cond1 = "before", cond2 = "after",
     fill = "condition", palette = "jco")

I have tried with geom_violin from ggplot2, but with no success at pairing the samples like ggpaired does

If you want `geom_violin`, why not use `geom_violin`? Seems to me that `ggpaired` makes boxplots. — Axeman, Sep 26 '19 at 18:40
That's what I'm trying. I have not seen a way to do paired samples like ggpaired! Of course I'm still a student at R for graphs — Gabriel G., Sep 26 '19 at 18:41
Ah ok, so you want a `ggplot2` answer, not a `ggpubr` answer? — Axeman, Sep 26 '19 at 18:41

score 3 · Accepted Answer · answered Sep 26 '19 at 18:47

You need to reshape your data first:

library(ggplot2)
before <-c(200.1, 190.9, 192.7, 213, 241.4, 196.9, 172.2, 185.5, 205.2, 193.7)
after <-c(392.9, 393.2, 345.1, 393, 434, 427.9, 422, 383.9, 392.3, 352.2)

d <- data.frame(before = before, after = after)
d$obs <- 1:nrow(d)
d2 <- tidyr::gather(d, time, value, -obs)

ggplot(d2, aes(time, value)) + 
  geom_violin() +
  geom_point() +
  geom_line(aes(group = obs)) +
  scale_x_discrete(limits = c('before', 'after'))

Pairing samples with violin plot in R

1 Answers1