3 layer donut chart in R-CodePudding

I am trying to recreate this image in R, however I am unable to work out how to have 3 layers to a donut chart - everything I find (for instance, webr::PieDonut) only allows 2. Using ggplot I am also unable to re-create it.

A MRE is:

library(ggplot2)
library(webr)
library(dplyr)

lexicon <- data.frame("Level1" = c(rep("Flavour", 11), rep("Appearance", 4)),
                  "Level2" = c(rep("Misc", 6), rep("Pungent", 5), rep("Colour", 4)),
                  "Level3" = c("Fresh", "Refreshing", "Soapy", "Minty", "Nutty", "Milky", "Peppery", "Sharp", "Horseradish", "Mustard hot", "Spicy", "Colourful"," Fresh Green", "Dark Green", "Bright Green")
)

PieDonut(lexicon, aes(Level1, Level2), title = "Salad Lexicon", showRatioDonut =FALSE, showRatioPie = FALSE)

ggplot(lexicon, aes(Level2, Level3, fill = Level1))  
  geom_col()  
  scale_fill_viridis_d()  
  coord_polar("y")

While the PieDonut works for 2 levels (not shown), it doesn't allow the final level to be included. The ggplot approach also does not work, as seen in the figure below.

How can I get this style of chart in R? Either with ggplot or base plotting.

CodePudding user response：

I think a nice alternative is to use geom_rect here after some data manipulation. Using the fill, color, and alpha scales can help improve the differentiation of categories. I would also use geom_textpath here, though I might go for circumferential labels if there is room to do so:

lexicon %>%
  mutate(top_level = Level1) %>%
  pivot_longer(1:3) %>%
  group_by(name, value) %>%
  mutate(width = n()) %>%
  unique() %>%
  arrange(name) %>%
  group_by(name) %>%
  mutate(ymid = as.numeric(sub("\\D ", "", name)),
         ymax = ymid   0.5, ymin = ymid - 0.5,
         xmin = c(0, head(cumsum(width), -1)),
         xmax = cumsum(width),
         xmid = (xmax   xmin) / 2) %>%
  ggplot(aes(xmid, ymid, fill = top_level))  
  geom_rect(aes(xmin = xmin, xmax = xmax, ymin = ymin, ymax = ymax,
                alpha = name, color = top_level))  
  geomtextpath::geom_textpath(aes(y = ymid   0.25, label = value, 
                                  group = value))  
  scale_alpha_manual(values = c(1, 0.3, 0.1))  
  scale_fill_manual(values = c("#cd9900", "#00817e"))  
  scale_colour_manual(values = c("#cd9900", "#00817e"))  
  scale_y_continuous(limits = c(-0.5, 3.6))  
  coord_polar()  
  theme_void()  
  theme(legend.position = "none")