ggplot2 pie and donut chart on same plot

Question

I am trying to replicate this with R ggplot. I have exactly the same data:

browsers<-structure(list(browser = structure(c(3L, 3L, 3L, 3L, 2L, 2L, 
2L, 1L, 5L, 5L, 4L), .Label = c("Chrome", "Firefox", "MSIE", 
"Opera", "Safari"), class = "factor"), version = structure(c(5L, 
6L, 7L, 8L, 2L, 3L, 4L, 1L, 10L, 11L, 9L), .Label = c("Chrome 10.0", 
"Firefox 3.5", "Firefox 3.6", "Firefox 4.0", "MSIE 6.0", "MSIE 7.0", 
"MSIE 8.0", "MSIE 9.0", "Opera 11.x", "Safari 4.0", "Safari 5.0"
), class = "factor"), share = c(10.85, 7.35, 33.06, 2.81, 1.58, 
13.12, 5.43, 9.91, 1.42, 4.55, 1.65), ymax = c(10.85, 18.2, 51.26, 
54.07, 55.65, 68.77, 74.2, 84.11, 85.53, 90.08, 91.73), ymin = c(0, 
10.85, 18.2, 51.26, 54.07, 55.65, 68.77, 74.2, 84.11, 85.53, 
90.08)), .Names = c("browser", "version", "share", "ymax", "ymin"
), row.names = c(NA, -11L), class = "data.frame")

and it looks like this:

> browsers
   browser      version  share   ymax   ymin
1     MSIE     MSIE 6.0  10.85  10.85   0.00
2     MSIE     MSIE 7.0   7.35  18.20  10.85
3     MSIE     MSIE 8.0  33.06  51.26  18.20
4     MSIE     MSIE 9.0   2.81  54.07  51.26
5  Firefox  Firefox 3.5   1.58  55.65  54.07
6  Firefox  Firefox 3.6  13.12  68.77  55.65
7  Firefox  Firefox 4.0   5.43  74.20  68.77
8   Chrome  Chrome 10.0   9.91  84.11  74.20
9   Safari   Safari 4.0   1.42  85.53  84.11
10  Safari   Safari 5.0   4.55  90.08  85.53
11   Opera   Opera 11.x   1.65  91.73  90.08

So far, I have plotted the individual components (i.e. the donut chart of the versions, and the pie chart of the browsers) like so:

ggplot(browsers) + geom_rect(aes(fill=version, ymax=ymax, ymin=ymin, xmax=4, xmin=3)) +
coord_polar(theta="y") + xlim(c(0, 4))

ggplot(browsers) + geom_bar(aes(x = factor(1), fill = browser),width = 1) +
coord_polar(theta="y")

The problem is, how do I combine the two to look like the topmost image? I have tried many ways, such as:

ggplot(browsers) + geom_rect(aes(fill=version, ymax=ymax, ymin=ymin, xmax=4, xmin=3)) +         geom_bar(aes(x = factor(1), fill = browser),width = 1) + coord_polar(theta="y") + xlim(c(0, 4)) 

But all my results are either twisted or end with an error message.

Answer 1

I find it easier to work in rectangular coordinates first, and when that is correct, then switch to polar coordinates. The x coordinate becomes radius in polar. So, in rectangular coordinates, the inside plot goes from zero to a number, like 3, and the outer band goes from 3 to 4.

For example

ggplot(browsers) + 
  geom_rect(aes(fill=version, ymax=ymax, ymin=ymin, xmax=4, xmin=3)) +
  geom_rect(aes(fill=browser, ymax=ymax, ymin=ymin, xmax=3, xmin=0)) +
  xlim(c(0, 4)) + 
  theme(aspect.ratio=1) 

Then, when you switch to polar, you get something like what you are looking for.

ggplot(browsers) + 
  geom_rect(aes(fill=version, ymax=ymax, ymin=ymin, xmax=4, xmin=3)) +
  geom_rect(aes(fill=browser, ymax=ymax, ymin=ymin, xmax=3, xmin=0)) +
  xlim(c(0, 4)) + 
  theme(aspect.ratio=1) +
  coord_polar(theta="y")  

This is a start, but may need to fine tune the dependency on y (or angle) and also work out the labeling / legend / coloring... By using rect for both the inner and outer rings, that should simplify adjusting the coloring. Also, it can be useful to use the reshape2::melt function to reorganize the data so then legend comes out correct by using group (or color).

Answer 2

Edit 2

My original answer is really dumb. Here is a much shorter version which does most of the work with a much simpler interface.

#' x      numeric vector for each slice
#' group  vector identifying the group for each slice
#' labels vector of labels for individual slices
#' col    colors for each group
#' radius radius for inner and outer pie (usually in [0,1])

donuts <- function(x, group = 1, labels = NA, col = NULL, radius = c(.7, 1)) {
  group <- rep_len(group, length(x))
  ug  <- unique(group)
  tbl <- table(group)[order(ug)]

  col <- if (is.null(col))
    seq_along(ug) else rep_len(col, length(ug))
  col.main <- Map(rep, col[seq_along(tbl)], tbl)
  col.sub  <- lapply(col.main, function(x) {
    al <- head(seq(0, 1, length.out = length(x) + 2L)[-1L], -1L)
    Vectorize(adjustcolor)(x, alpha.f = al)
  })

  plot.new()

  par(new = TRUE)
  pie(x, border = NA, radius = radius[2L],
      col = unlist(col.sub), labels = labels)

  par(new = TRUE)
  pie(x, border = NA, radius = radius[1L],
      col = unlist(col.main), labels = NA)
}

par(mfrow = c(1,2), mar = c(0,4,0,4))
with(browsers,
     donuts(share, browser, sprintf('%s: %s%%', version, share),
            col = c('cyan2','red','orange','green','dodgerblue2'))
)

with(mtcars,
     donuts(mpg, interaction(gear, cyl), rownames(mtcars))
)

---

Original post

You guys don't have givemedonutsorgivemedeath function? Base graphics are always the way to go for very detailed things like this. Couldn't think of an elegant way to plot the center pie labels, though.

givemedonutsorgivemedeath('~/desktop/donuts.pdf') 

Gives me

Note that in ?pie you see

Pie charts are a very bad way of displaying information.

code:

browsers <- structure(list(browser = structure(c(3L, 3L, 3L, 3L, 2L, 2L, 
  2L, 1L, 5L, 5L, 4L), .Label = c("Chrome", "Firefox", "MSIE", 
  "Opera", "Safari"), class = "factor"), version = structure(c(5L, 
  6L, 7L, 8L, 2L, 3L, 4L, 1L, 10L, 11L, 9L), .Label = c("Chrome 10.0", 
  "Firefox 3.5", "Firefox 3.6", "Firefox 4.0", "MSIE 6.0", "MSIE 7.0", 
  "MSIE 8.0", "MSIE 9.0", "Opera 11.x", "Safari 4.0", "Safari 5.0"), 
  class = "factor"), share = c(10.85, 7.35, 33.06, 2.81, 1.58, 
  13.12, 5.43, 9.91, 1.42, 4.55, 1.65), ymax = c(10.85, 18.2, 51.26, 
  54.07, 55.65, 68.77, 74.2, 84.11, 85.53, 90.08, 91.73), ymin = c(0, 
  10.85, 18.2, 51.26, 54.07, 55.65, 68.77, 74.2, 84.11, 85.53, 
  90.08)), .Names = c("browser", "version", "share", "ymax", "ymin"),
  row.names = c(NA, -11L), class = "data.frame")

browsers$total <- with(browsers, ave(share, browser, FUN = sum))

givemedonutsorgivemedeath <- function(file, width = 15, height = 11) {
  ## house keeping 
  if (missing(file)) file <- getwd()
  plot.new(); op <- par(no.readonly = TRUE); on.exit(par(op))

  pdf(file, width = width, height = height, bg = 'snow')

  ## useful values and colors to work with
  ## each group will have a specific color
  ## each subgroup will have a specific shade of that color
  nr <- nrow(browsers)
  width <- max(sqrt(browsers$share)) / 0.8

  tbl <- with(browsers, table(browser)[order(unique(browser))])
  cols <- c('cyan2','red','orange','green','dodgerblue2')
  cols <- unlist(Map(rep, cols, tbl))

  ## loop creates pie slices
  plot.new()
  par(omi = c(0.5,0.5,0.75,0.5), mai = c(0.1,0.1,0.1,0.1), las = 1)
  for (i in 1:nr) {
    par(new = TRUE)

    ## create color/shades
    rgb <- col2rgb(cols[i])
    f0 <- rep(NA, nr)
    f0[i] <- rgb(rgb[1], rgb[2], rgb[3], 190 / sequence(tbl)[i], maxColorValue = 255)

    ## stick labels on the outermost section
    lab <- with(browsers, sprintf('%s: %s', version, share))
    if (with(browsers, share[i] == max(share))) {
      lab0 <- lab
    } else lab0 <- NA

    ## plot the outside pie and shades of subgroups
    pie(browsers$share, border = NA, radius = 5 / width, col = f0, 
        labels = lab0, cex = 1.8)

    ## repeat above for the main groups
    par(new = TRUE)
    rgb <- col2rgb(cols[i])
    f0[i] <- rgb(rgb[1], rgb[2], rgb[3], maxColorValue = 255)

    pie(browsers$share, border = NA, radius = 4 / width, col = f0, labels = NA)
  }

  ## extra labels on graph

  ## center labels, guess and check?
  text(x = c(-.05, -.05, 0.15, .25, .3), y = c(.08, -.12, -.15, -.08, -.02), 
       labels = unique(browsers$browser), col = 'white', cex = 1.2)

  mtext('Browser market share, April 2011', side = 3, line = -1, adj = 0, 
        cex = 3.5, outer = TRUE)
  mtext('stackoverflow.com:::maryam', side = 3, line = -3.6, adj = 0,
        cex = 1.75, outer = TRUE, font = 3)
  mtext('/questions/26748069/ggplot2-pie-and-donut-chart-on-same-plot',
        side = 1, line = 0, adj = 1.0, cex = 1.2, outer = TRUE, font = 3)
  dev.off()
}

givemedonutsorgivemedeath('~/desktop/donuts.pdf')

---

Edit 1

width <- 5

tbl <- table(browsers$browser)[order(unique(browsers$browser))]
col.main <- Map(rep, seq_along(tbl), tbl)
col.sub  <- lapply(col.main, function(x)
  Vectorize(adjustcolor)(x, alpha.f = seq_along(x) / length(x)))

plot.new()

par(new = TRUE)
pie(browsers$share, border = NA, radius = 5 / width,
    col = unlist(col.sub), labels = browsers$version)

par(new = TRUE)
pie(browsers$share, border = NA, radius = 4 / width,
    col = unlist(col.main), labels = NA)

Answer 3

I created a general purpose donuts plot function to do this, which could

• Draw ring plot, i.e. draw pie chart for panel and colorize each circular sector by given percentage pctr and colors cols. The ring width could be tuned by outradius>radius>innerradius.
• Overlay several ring plot together.

The main function actually draw a bar chart and bend it into a ring, hence it is something between a pie chart and a bar chart.

Example Pie Chart, two rings:

Browser Pie Chart

donuts_plot <- function(
                        panel = runif(3), # counts
                        pctr = c(.5,.2,.9), # percentage in count
                        legend.label='',
                        cols = c('chartreuse', 'chocolate','deepskyblue'), # colors
                        outradius = 1, # outter radius
                        radius = .7,   # 1-width of the donus 
                        add = F,
                        innerradius = .5, # innerradius, if innerradius==innerradius then no suggest line
                        legend = F,
                        pilabels=F,
                        legend_offset=.25, # non-negative number, legend right position control
                        borderlit=c(T,F,T,T)
                        ){
    par(new=add)
    if(sum(legend.label=='')>=1) legend.label=paste("Series",1:length(pctr))
    if(pilabels){
        pie(panel, col=cols,border = borderlit[1],labels = legend.label,radius = outradius)
    }
    panel = panel/sum(panel)

    pctr2= panel*(1 - pctr)
    pctr3 = c(pctr,pctr)
    pctr_indx=2*(1:length(pctr))
    pctr3[pctr_indx]=pctr2
    pctr3[-pctr_indx]=panel*pctr
    cols_fill = c(cols,cols)
    cols_fill[pctr_indx]='white'
    cols_fill[-pctr_indx]=cols
    par(new=TRUE)
    pie(pctr3, col=cols_fill,border = borderlit[2],labels = '',radius = outradius)
    par(new=TRUE)
    pie(panel, col='white',border = borderlit[3],labels = '',radius = radius)
    par(new=TRUE)
    pie(1, col='white',border = borderlit[4],labels = '',radius = innerradius)
    if(legend){
        # par(mar=c(5.2, 4.1, 4.1, 8.2), xpd=TRUE)
        legend("topright",inset=c(-legend_offset,0),legend=legend.label, pch=rep(15,'.',length(pctr)), 
               col=cols,bty='n')
    }
    par(new=FALSE)
}
## col- > subcor(change hue/alpha)
subcolors <- function(.dta,main,mainCol){
    tmp_dta = cbind(.dta,1,'col')
    tmp1 = unique(.dta[[main]])
    for (i in 1:length(tmp1)){
        tmp_dta$"col"[.dta[[main]] == tmp1[i]] = mainCol[i]
    }
    u <- unlist(by(tmp_dta$"1",tmp_dta[[main]],cumsum))
    n <- dim(.dta)[1]
    subcol=rep(rgb(0,0,0),n);
    for(i in 1:n){
        t1 = col2rgb(tmp_dta$col[i])/256
        subcol[i]=rgb(t1[1],t1[2],t1[3],1/(1+u[i]))
    }
    return(subcol);
}
### Then get the plot is fairly easy:
# INPUT data
browsers <- structure(list(browser = structure(c(3L, 3L, 3L, 3L, 2L, 2L, 
                                                 2L, 1L, 5L, 5L, 4L), 
                                               .Label = c("Chrome", "Firefox", "MSIE","Opera", "Safari"),class = "factor"), 
                           version = structure(c(5L,6L, 7L, 8L, 2L, 3L, 4L, 1L, 10L, 11L, 9L), 
                                               .Label = c("Chrome 10.0", "Firefox 3.5", "Firefox 3.6", "Firefox 4.0", "MSIE 6.0", 
                                                          "MSIE 7.0","MSIE 8.0", "MSIE 9.0", "Opera 11.x", "Safari 4.0", "Safari 5.0"),
                                               class = "factor"), 
                           share = c(10.85, 7.35, 33.06, 2.81, 1.58,13.12, 5.43, 9.91, 1.42, 4.55, 1.65), 
                           ymax = c(10.85, 18.2, 51.26,54.07, 55.65, 68.77, 74.2, 84.11, 85.53, 90.08, 91.73), 
                           ymin = c(0,10.85, 18.2, 51.26, 54.07, 55.65, 68.77, 74.2, 84.11, 85.53,90.08)),
                      .Names = c("browser", "version", "share", "ymax", "ymin"),
                      row.names = c(NA, -11L), class = "data.frame")
## data clean
browsers=browsers[order(browsers$browser,browsers$share),]
arr=aggregate(share~browser,browsers,sum)
### choose your cols
mainCol =  c('chartreuse3', 'chocolate3','deepskyblue3','gold3','deeppink3')
donuts_plot(browsers$share,rep(1,11),browsers$version,
        cols=subcolors(browsers,"browser",mainCol),
        legend=F,pilabels = T,borderlit = rep(F,4) )
donuts_plot(arr$share,rep(1,5),arr$browser,
        cols=mainCol,pilabels=F,legend=T,legend_offset=-.02,
        outradius = .71,radius = .0,innerradius=.0,add=T,
        borderlit = rep(F,4) )
###end of line

Answer 4

you can get something similar using the package ggsunburst

# using your data without "ymax" and "ymin"
browsers <- structure(list(browser = structure(c(3L, 3L, 3L, 3L, 2L, 2L,
2L, 1L, 5L, 5L, 4L), .Label = c("Chrome", "Firefox", "MSIE",
"Opera", "Safari"), class = "factor"), version = structure(c(5L,
6L, 7L, 8L, 2L, 3L, 4L, 1L, 10L, 11L, 9L), .Label = c("Chrome 10.0",
"Firefox 3.5", "Firefox 3.6", "Firefox 4.0", "MSIE 6.0", "MSIE 7.0",
"MSIE 8.0", "MSIE 9.0", "Opera 11.x", "Safari 4.0", "Safari 5.0"
), class = "factor"), share = c(10.85, 7.35, 33.06, 2.81, 1.58,
13.12, 5.43, 9.91, 1.42, 4.55, 1.65)), .Names = c("parent", "node", "size")
, row.names = c(NA, -11L), class = "data.frame")

# add column browser to be used for colouring
browsers$browser <- browsers$parent

# write data.frame into csv file
write.table(browsers, file = 'browsers.csv', row.names = F, sep = ",")

# install ggsunburst
if (!require("ggplot2")) install.packages("ggplot2")
if (!require("rPython")) install.packages("rPython")
install.packages("http://genome.crg.es/~didac/ggsunburst/ggsunburst_0.0.9.tar.gz", repos=NULL, type="source")
library(ggsunburst)

# generate data structure
sb <- sunburst_data('browsers.csv', type = 'node_parent', sep = ",", node_attributes = c("browser","size"))

# add name as browser attribute for colouring to internal nodes
sb$rects[!sb$rects$leaf,]$browser <- sb$rects[!sb$rects$leaf,]$name

# plot adding geom_text layer for showing the "size" value
p <- sunburst(sb, rects.fill.aes = "browser", node_labels = T, node_labels.min = 15)
p + geom_text(data = sb$leaf_labels,
    aes(x=x, y=0.1, label=paste(size,"%"), angle=angle, hjust=hjust), size = 2)

Answer 5

@rawr's solution is really nice, however, the labels will be overlapped if there are too many. Inspired by @user3969377 and @FlorianGD, I got a new solution using ggplot2 and ggrepel.

1. prepare data

browsers$ymax <- cumsum(browsers$share) # fed to geom_rect() in piedonut()
browsers$ymin <- browsers$ymax - browsers$share # fed to geom_rect() in piedonut()

browsers$share_browser <- sum(browsers$share[browsers$browser == unique(browsers$browser)[1]]) # "_browser" means at browser level
browsers$ymax_browser <- browsers$share_browser[browsers$browser == unique(browsers$browser)[1]][1]
for (z in 2:length(unique(browsers$browser))) {
  browsers$share_browser[browsers$browser == unique(browsers$browser)[z]] <- sum(browsers$share[browsers$browser == unique(browsers$browser)[z]])
  browsers$ymax_browser[browsers$browser == unique(browsers$browser)[z]] <- browsers$ymax_browser[browsers$browser == unique(browsers$browser)[z-1]][1] + browsers$share_browser[browsers$browser == unique(browsers$browser)[z]][1]
}
browsers$ymin_browser <- browsers$ymax_browser - browsers$share_browser

2. write piedonut function

piedonut <- function(data, cols = c('cyan2','red','orange','green','dodgerblue2'), force = 80, nudge_x = 3, nudge_y = 10) { # force, nudge_x, nudge_y are parameters to fine tune positions of the labels by geom_label_repel.
  nr <- nrow(data)
  # width <- max(sqrt(data$share)) / 0.1
  
  tbl <- with(data, table(browser)[order(unique(browser))])
  cols <- unlist(Map(rep, cols, tbl))
  col_subnum <- unlist(Map(rep, 255/tbl,tbl))
  
  col <- rep(NA, nr)
  col_browser <- rep(NA, nr)
  for (i in 1:nr) {
    ## create color/shades
    rgb <- col2rgb(cols[i])
    col[i] <- rgb(rgb[1], rgb[2], rgb[3],  col_subnum[i]*sequence(tbl)[i], maxColorValue = 255)
  
    rgb <- col2rgb(cols[i])
    col_browser[i] <- rgb(rgb[1], rgb[2], rgb[3], maxColorValue = 255)
  }
  #col
  # set labels positions
  x.breaks <- seq(1, 1.8, length.out = nr)
  y.breaks <- cumsum(data$share)-data$share/2
  ggplot(data) +
    geom_rect(aes(ymax = ymax, ymin = ymin, xmax=4, xmin=1), fill=col) +
    geom_rect(aes(ymax=ymax_browser, ymin=ymin_browser, xmax=1, xmin=0), fill=col_browser) +
    coord_polar(theta = 'y') +
    theme(axis.ticks = element_blank(),
          axis.title = element_blank(),
          axis.text = element_blank(),
          panel.grid = element_blank(),
          panel.background = element_blank()) +
    geom_label_repel(aes(x = x.breaks, y = y.breaks, label = sprintf("%s: %s%%",data$version, data$share)),
                     force = force,
                     nudge_x = nudge_x,
                     nudge_y = nudge_y)
}

3. get the piedonut

cols <- c('cyan2','red','orange','green','dodgerblue2')

pdf('~/Downloads/donuts.pdf', width = 10, height = 10, bg = "snow")
par(omi = c(0.5,0.5,0.75,0.5), mai = c(0.1,0.1,0.1,0.1), las = 1)
print(piedonut(data = browsers, cols = cols, force = 80, nudge_x = 3, nudge_y = 10))
dev.off()

Answer 6

You can create a pie-donut chart like the one below with only one code line using the PieDonut() function from the webr package.

# loadin the libraries
library(ggplot2)
library(webr)

# replicating the table
browsers<-structure(
  list(browser = structure(c(3L, 3L, 3L, 3L, 2L, 2L, 2L, 1L, 5L, 5L, 4L),
                           .Label = c("Chrome", "Firefox", "MSIE", "Opera", "Safari"), class = "factor"), 
       version = structure(c(5L, 6L, 7L, 8L, 2L, 3L, 4L, 1L, 10L, 11L, 9L), 
                           .Label = c("Chrome 10.0", "Firefox 3.5", "Firefox 3.6", "Firefox 4.0", "MSIE 6.0", "MSIE 7.0", "MSIE 8.0", "MSIE 9.0", "Opera 11.x", "Safari 4.0", "Safari 5.0"), class = "factor"), 
       share = c(10.85, 7.35, 33.06, 2.81, 1.58, 13.12, 5.43, 9.91, 1.42, 4.55, 1.65), 
       ymax = c(10.85, 18.2, 51.26, 54.07, 55.65, 68.77, 74.2, 84.11, 85.53, 90.08, 91.73), 
       ymin = c(0, 10.85, 18.2, 51.26, 54.07, 55.65, 68.77, 74.2, 84.11, 85.53, 90.08)), 
  .Names = c("browser", "version", "share", "ymax", "ymin"), row.names = c(NA, -11L), class = "data.frame")

# building the pie-donut chart
PieDonut(browsers, aes(browser, version, count=share),
         title = "Browser market share, April, 2011",
         ratioByGroup = FALSE)

Answer 7

I used floating.pie instead of ggplot2 to create two overlapping pie charts:

library(plotrix)

# browser data without "ymax" and "ymin"
browsers <-
    structure(
        list(
            browser = structure(
                c(3L, 3L, 3L, 3L, 2L, 2L,
                  2L, 1L, 5L, 5L, 4L),
                .Label = c("Chrome", "Firefox", "MSIE",
                           "Opera", "Safari"),
                class = "factor"
            ),
            version = structure(
                c(5L,
                  6L, 7L, 8L, 2L, 3L, 4L, 1L, 10L, 11L, 9L),
                .Label = c(
                    "Chrome 10.0",
                    "Firefox 3.5",
                    "Firefox 3.6",
                    "Firefox 4.0",
                    "MSIE 6.0",
                    "MSIE 7.0",
                    "MSIE 8.0",
                    "MSIE 9.0",
                    "Opera 11.x",
                    "Safari 4.0",
                    "Safari 5.0"
                ),
                class = "factor"
            ),
            share = c(10.85, 7.35, 33.06, 2.81, 1.58,
                      13.12, 5.43, 9.91, 1.42, 4.55, 1.65)
        ),
        .Names = c("parent", "node", "size")
        ,
        row.names = c(NA,-11L),
        class = "data.frame"
    )

# aggregate data for the browser pie chart
browser_data <-
    aggregate(browsers$share,
              by = list(browser = browsers$browser),
              FUN = sum)

# order version data by browser so it will line up with browser pie chart
version_data <- browsers[order(browsers$browser), ]

browser_colors <- c('#85EA72', '#3B3B3F', '#71ACE9', '#747AE6', '#F69852')

# adjust these as desired (currently colors all versions the same as browser)
version_colors <-
    c(
        '#85EA72',
        '#3B3B3F',
        '#3B3B3F',
        '#3B3B3F',
        '#71ACE9',
        '#71ACE9',
        '#71ACE9',
        '#71ACE9',
        '#747AE6',
        '#F69852',
        '#F69852'
    )

# format labels to display version and % market share
version_labels <- paste(version_data$version, ": ", version_data$share, "%", sep = "")

# coordinates for the center of the chart
center_x <- 0.5
center_y <- 0.5

plot.new()

# draw version pie chart first
version_chart <-
    floating.pie(
        xpos = center_x,
        ypos = center_y,
        x = version_data$share,
        radius = 0.35,
        border = "white",
        col = version_colors
    )

# add labels for version pie chart
pie.labels(
    x = center_x,
    y = center_y,
    angles = version_chart,
    labels = version_labels,
    radius = 0.38,
    bg = NULL,
    cex = 0.8,
    font = 2,
    col = "gray40"
)

# overlay browser pie chart
browser_chart <-
    floating.pie(
        xpos = center_x,
        ypos = center_y,
        x = browser_data$x,
        radius = 0.25,
        border = "white",
        col = browser_colors
    )

# add labels for browser pie chart
pie.labels(
    x = center_x,
    y = center_y,
    angles = browser_chart,
    labels = browser_data$browser,
    radius = 0.125,
    bg = NULL,
    cex = 0.8,
    font = 2,
    col = "white"
)