Violin plot of a data frame

Question

I have a data.frame, for example:

df = data.frame(AAA=rnorm(100,1,1),BBB=rnorm(100,2,1.5),CCC=rnorm(100,1.5,1.2))

And I'd like to plot each of its columns in a joint violin plot.

Here's where I'm at so far:

names(df)[1] = 'x'
do.call('vioplot', c(df,col="red",drawRect=FALSE))

What I want to do next is to plot the colnames of df as x-axis labels rather than the default x-axis labels of vioplot and in addition in a way that they don't run over each other. I imagine this can be achieved either by spreading the columns of df in the plot or by slanting the x-axis labels. But I can't figure that out.

Answer 1

Probably easier to use ggplot

df = data.frame(AAA=rnorm(100,1,1),
                BBB=rnorm(100,2,1.5),
                CCC=rnorm(100,1.5,1.2))

Need to transform the data into something ggplot can handle:

df.m <- reshape2::melt(df, id.vars = NULL)

and plot:

library(ggplot2)
ggplot(df.m, aes(x = variable, y = value)) + geom_violin()

Answer 2

I like the ggplot solution the best, but here is how you would do it with do.call:

do.call(vioplot,c(unname(df),col='red',drawRect=FALSE,names=list(names(df))))

Notably, you wouldn't have to do names(df)[1] = 'x' because you remove the names with unname.