In ggplot2, how to add a white hole in the middle of the pie chart-CodePudding

In ggplot2, how to add a white hole in the middle of the pie chart? Please refer to below code for current plot (the left plot) . Thanks!

library(tidyverse)
pie_data <- data.frame(category=c('A','B','C','A','B','C'),
                       year=c(2020,2020,2020,2021,2021,2021),
                       sales=c(40,30,20,10,15,10))




pie_data %>% ggplot(aes(x=factor(year),y=sales,fill=category)) 
  geom_col(position='fill',width=1,color='white') 
 coord_polar(theta = 'y') 
  theme_void()

CodePudding user response：

Just widen the limits of your x axis (it's easier to do this if you don't convert the year into a factor):

pie_data %>% ggplot(aes(x = year, y = sales, fill = category)) 
  geom_col(position = 'fill', width = 1, color = 'white')  
  coord_polar(theta = 'y')   
  lims(x = c(2019, 2022))  
  theme_void()

You can control the size of the white hole by changing 2019 in the above code. The earlier the year, the larger the hole:

pie_data %>% ggplot(aes(x = year, y = sales, fill = category)) 
  geom_col(position = 'fill', width = 1, color = 'white')  
  coord_polar(theta = 'y')   
  lims(x = c(2017, 2022))  
  theme_void()

CodePudding user response：

You can add an hollow bar at the center:

  pie_data %>% ggplot(aes(x=factor(year),y=sales,fill=category)) 
      geom_col(position='fill',width=1,color='white') 
      coord_polar(theta = 'y') 
      geom_col(aes(x=0,y=0)) 
      theme_void()

if you want a larger circle, use a negative x coordinate:

geom_col(aes(x=-1,y=0))