Violin Plots in R

How to create violin plots in R with Plotly.

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Plotly is a free and open-source graphing library for R. We recommend you read our Getting Started guide for the latest installation or upgrade instructions, then move on to our Plotly Fundamentals tutorials or dive straight in to some Basic Charts tutorials.

Basic Violin Plot

library(plotly)

df <- read.csv("https://raw.githubusercontent.com/plotly/datasets/master/violin_data.csv")

fig <- df %>%
  plot_ly(
    y = ~total_bill,
    type = 'violin',
    box = list(
      visible = T
    ),
    meanline = list(
      visible = T
    ),
    x0 = 'Total Bill'
  ) 

fig <- fig %>%
  layout(
    yaxis = list(
      title = "",
      zeroline = F
    )
  )

fig

Multiple Trace

library(plotly)

df <- read.csv("https://raw.githubusercontent.com/plotly/datasets/master/violin_data.csv")

fig <- df %>%
  plot_ly(
    x = ~day,
    y = ~total_bill,
    split = ~day,
    type = 'violin',
    box = list(
      visible = T
    ),
    meanline = list(
      visible = T
    )
  ) 

fig <- fig %>%
  layout(
    xaxis = list(
      title = "Day"
    ),
    yaxis = list(
      title = "Total Bill",
      zeroline = F
    )
  )

fig

Grouped Violin Plot

library(plotly)

df <- read.csv("https://raw.githubusercontent.com/plotly/datasets/master/violin_data.csv")

fig <- df %>%
  plot_ly(type = 'violin') 
fig <- fig %>%
  add_trace(
    x = ~day[df$sex == 'Male'],
    y = ~total_bill[df$sex == 'Male'],
    legendgroup = 'M',
    scalegroup = 'M',
    name = 'M',
    box = list(
      visible = T
    ),
    meanline = list(
      visible = T
    ),
    color = I("blue")
  ) 
fig <- fig %>%
  add_trace(
    x = ~day[df$sex == 'Female'],
    y = ~total_bill[df$sex == 'Female'],
    legendgroup = 'F',
    scalegroup = 'F',
    name = 'F',
    box = list(
      visible = T
    ),
    meanline = list(
      visible = T
    ),
    color = I("pink")
  ) 

fig <- fig %>%
  layout(
    yaxis = list(
      zeroline = F
    ),
    violinmode = 'group'
  )

fig

Split Violin Plot

library(plotly)

df <- read.csv("https://raw.githubusercontent.com/plotly/datasets/master/violin_data.csv")

fig <- df %>%
  plot_ly(type = 'violin') 
fig <- fig %>%
  add_trace(
    x = ~day[df$smoker == 'Yes'],
    y = ~total_bill[df$smoker == 'Yes'],
    legendgroup = 'Yes',
    scalegroup = 'Yes',
    name = 'Yes',
    side = 'negative',
    box = list(
      visible = T
    ),
    meanline = list(
      visible = T
    ),
    color = I("blue")
  ) 
fig <- fig %>%
  add_trace(
    x = ~day[df$smoker == 'No'],
    y = ~total_bill[df$smoker == 'No'],
    legendgroup = 'No',
    scalegroup = 'No',
    name = 'No',
    side = 'positive',
    box = list(
      visible = T
    ),
    meanline = list(
      visible = T
    ),
    color = I("green")
  ) 

fig <- fig %>%
  layout(
    xaxis = list(
      title = ""  
    ),
    yaxis = list(
      title = "",
      zeroline = F
    ),
    violingap = 0,
    violingroupgap = 0,
    violinmode = 'overlay'
  )

fig

Advanced Violin Plot

library(plotly)

df <- read.csv("https://raw.githubusercontent.com/plotly/datasets/master/violin_data.csv")

pointposMale <- c(-0.9,-1.1,-0.6,-0.3)
pointposFemale <- c(0.45,0.55,1,0.4)
showLegend <- c(T,F,F,F)

fig <- plot_ly(type = 'violin')

i = 0
for (i in 1:length(unique(df$day))) {
 fig <- add_trace(
    fig,
    x = df$day[df$sex == 'Male' & df$day == unique(df$day)[i]],
    y = df$total_bill[df$sex == 'Male' & df$day == unique(df$day)[i]],
    hoveron = "points+kde",
    legendgroup = 'M',
    scalegroup = 'M',
    name = 'M',
    side = 'negative',
    box = list(
      visible = T
    ),
    points = 'all',
    pointpos = pointposMale[i],
    jitter = 0,
    scalemode = 'count',
    meanline = list(
      visible = T
    ),
    color = I("#8dd3c7"),
    marker = list(
      line = list(
        width = 2,
        color = "#8dd3c7"
      ),
      symbol = 'line-ns'
    ),
    showlegend = showLegend[i]
    ) 

fig <- fig %>%
    add_trace(
      x = df$day[df$sex == 'Female' & df$day == unique(df$day)[i]],
      y = df$total_bill[df$sex == 'Female' & df$day == unique(df$day)[i]],
      hoveron = "points+kde",
      legendgroup = 'F',
      scalegroup = 'F',
      name = 'F',
      side = 'positive',
      box = list(
        visible = T
      ),
      points = 'all',
      pointpos = pointposFemale[i],
      jitter = 0,
      scalemode = 'count',
      meanline = list(
        visible = T
      ),
      color = I("#bebada"),
      marker = list(
        line = list(
          width = 2,
          color = "#bebada"
        ),
        symbol = 'line-ns'
      ),
      showlegend = showLegend[i]
  )
}

fig <- layout(
  fig,
  title = "Total bill distribution<br><i>scaled by number of bills per gender",
  yaxis = list(
    zeroline = F
  ),
  violingap = 0,
  violingroupgap = 0,
  violinmode = 'overlay',
  legend = list(
    tracegroupgap = 0
  )
)

fig

Reference

See https://plotly.com/r/reference/ for more information and options!

What About Dash?

Dash for R is an open-source framework for building analytical applications, with no Javascript required, and it is tightly integrated with the Plotly graphing library.

Learn about how to install Dash for R at https://dashr.plot.ly/installation.

Everywhere in this page that you see fig, you can display the same figure in a Dash for R application by passing it to the figure argument of the Graph component from the built-in dashCoreComponents package like this:

library(plotly)

fig <- plot_ly() 
# fig <- fig %>% add_trace( ... )
# fig <- fig %>% layout( ... ) 

library(dash)
library(dashCoreComponents)
library(dashHtmlComponents)

app <- Dash$new()
app$layout(
    htmlDiv(
        list(
            dccGraph(figure=fig) 
        )
     )
)

app$run_server(debug=TRUE, dev_tools_hot_reload=FALSE)