Making a scatter plot of multiple pie charts of differing sizes, using ggplot2 in R

Question

I have a data frame containing the following data:

> data_graph
# A tibble: 12 x 4
# Groups:   ATTPRO, ATTMAR [?]
       x     y group    nb
   <dbl> <dbl> <chr> <int>
 1     0     0     1  1060
 2     0     0     2   361
 3     0     0     3   267
 4     0     1     1   788
 5     0     1     2   215
 6     0     1     3    80
 7     1     0     1   485
 8     1     0     2   168
 9     1     0     3   101
10     1     1     1  6306
11     1     1     2  1501
12     1     1     3   379

My objective is to have the following chart:

Both x and y, qualitative variables, to be put as X/Y axis
nb, quantitative variable, representing pie size
group, qualitative variable, representing pie parts

The best result approching this using ggplot2 package is only giving me bubbles, with this code. I can't find a solution to put pies within it:

library(ggplot2)
  ggplot(data_graph, aes(y = factor(y),x = factor(x))) +
  geom_point(aes(colour = group, size = nb)) +
  theme_bw() + 
  cale_size(range = c(1, 20)) +
  labs(x = "x", y = "y", color = "group", size = "nb")

Using scatterpie package did not help that much. This time pies are well drawn, but I can't find a way to use nb to define pie size. Also, x and y are treated as quantitative variables (I tried factor() without any chance) instead of qualitative ones. The result is pretty ugly, without a full legend.

> tmp
  x y    A    B   C
1 0 0 1060  361 267
2 0 1  788  215  80
3 1 0  485  168 101
4 1 1 6306 1501 379

library(scatterpie)
ggplot() +
   geom_scatterpie(aes(x = x, y = y), data = tmp, cols = c("A", "B", "C")) +
   coord_fixed()

How can this code be altered in order to have the 1st chart with the 2nd one's pies?

Please use less images and especially add the used data samples as part of the question, if you would like increase the probability to get an answer. — Heikki, Dec 02 '17 at 22:50
Generally, we want to have the data pasted as the output of `dput()`, so we can just copy it into our code and directly recreate the data frame. — Claus Wilke, Dec 02 '17 at 23:56

Claus Wilke · Accepted Answer · 2017-12-02T23:58:44.927

This seems to be a case for geom_arc_bar() from ggforce, with some dplyr magic. This treats x and y as continuous variables, but that's not a problem, you can pretend they are discrete by setting the right axis settings.

The data:

data_graph <- read.table(text = "x     y group    nb
1     0     0     1  1060
2     0     0     2   361
3     0     0     3   267
4     0     1     1   788
5     0     1     2   215
6     0     1     3    80
7     1     0     1   485
8     1     0     2   168
9     1     0     3   101
10     1     1     1  6306
11     1     1     2  1501
12     1     1     3   379", header = TRUE)

The code:

library(ggforce)
library(dplyr)

# make group a factor
data_graph$group <- factor(data_graph$group)

# add case variable that separates the four pies
data_graph <- cbind(data_graph, case = rep(c("Aaaa", "Bbbb", "Cccc", "Dddd"), each = 3))

# calculate the start and end angles for each pie
data_graph <- left_join(data_graph,
  data_graph %>% 
    group_by(case) %>%
    summarize(nb_total = sum(nb))) %>%
  group_by(case) %>%
  mutate(nb_frac = 2*pi*cumsum(nb)/nb_total,
         start = lag(nb_frac, default = 0))

# position of the labels
data_labels <- data_graph %>% 
  group_by(case) %>%
  summarize(x = x[1], y = y[1], nb_total = nb_total[1])

# overall scaling for pie size
scale = .5/sqrt(max(data_graph$nb_total))

# draw the pies
ggplot(data_graph) + 
  geom_arc_bar(aes(x0 = x, y0 = y, r0 = 0, r = sqrt(nb_total)*scale,
                   start = start, end = nb_frac, fill = group)) +
  geom_text(data = data_labels,
            aes(label = case, x = x, y = y + scale*sqrt(nb_total) + .05),
            size =11/.pt, vjust = 0) +
  coord_fixed() +
  scale_x_continuous(breaks = c(0, 1), labels = c("X0", "X1"), name = "x axis") +
  scale_y_continuous(breaks = c(0, 1), labels = c("Y0", "Y1"), name = "y axis") +
  theme_minimal() +
  theme(panel.grid.minor = element_blank())

Making a scatter plot of multiple pie charts of differing sizes, using ggplot2 in R

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