CODEWITHSUNDEEP
rggplot2violin-plot
Alexander
Alexander

Reputation: 33

Violin Plot in R using ggplot2 on multiple data columns

I am new to R, and trying to make violin plots of species count data for various species at each sampling depth. The data looks like the following

    Depth Cd Cf Cl
1  3.6576  0  2  0
2  4.0000  2 13  0
3  4.2672  0  0  0
4 13.1064  0  2  0
5 14.0000  3 17 10
6 17.0000  0  0  0

With species in columns 2-5 and depth in column one. I am attempting to use ggplot2 in R but assume the data are not organized in a way that can be used by ggplot2. Ideally I would like the depth to be the y-axis and the species along the x-axis, with violin plots for each. Thank you for your help. Alex

Upvotes: 3

Views: 6540

Answers (2)

Thomas K
Thomas K

Reputation: 3311

Like you suspected already, you need to reshape your data. Using tidyr::gather changes the format from "wide" to "long", which is necessary in this case for plotting species on the x-axis. Furthermore, you need to expand your count data which you can achieve with slice.


library(tidyverse)

zz <- "Depth Cd Cf Cl
1  3.6576  0  2  0
2  4.0000  2 13  0
3  4.2672  0  0  0
4 13.1064  0  2  0
5 14.0000  3 17 10
6 17.0000  0  0  0"

my_dat <- read.table(text = zz, header = T)

my_dat %>% 
  gather(species, val, -Depth) %>% 
  slice(rep(row_number(), val)) %>%
  ggplot(aes(species, Depth)) +
  geom_violin(adjust = .5)

Upvotes: 2

Axeman
Axeman

Reputation: 35227

Reshape your data first:

library(tidyverse)

my_dat2 <- my_dat %>% 
  gather(species, val, -Depth) %>% 
  slice(rep(row_number(), val)) %>% 
  select(-val)

ggplot(my_dat2, aes(species, Depth)) +
  geom_violin()

enter image description here

Note that Cl only has a single line because you have only a singly depth.

Upvotes: 3

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