R - pie chart in facet

Question

I have four pie charts which I need them all to be displayed in two lines and two columns. I use the below script to display the one:

slices <- c(39, 7, 13)
lbls <- c("monthly", "daily", "weekly")
pct <- slices
lbls <- paste(lbls, pct) 
pie(slices,labels = lbls, col=rainbow(length(lbls)),
    main="Purchased Products")

How can I create three more of them with different main titles each time if the other three pie charts values are as below:

slices <- c(40, 5, 12)
lbls <- c("monthly", "daily", "weekly")

slices <- c(15, 27, 47)
lbls <- c("monthly", "daily", "weekly")

slices <- c(58, 47, 2)
lbls <- c("monthly", "daily", "weekly")

Answer 1

Something like will work. You just have to change how your data is formatted and use ggplot2 which is in the tidyverse.

library(tidyverse)

df1 <- expand_grid(pie = 1:4, labels = c("monthly", "daily", "weekly"))
df2 <- tibble(slices = c(39, 7, 13,
                         40, 5, 12,
                         15, 27, 47,
                         58, 47, 2))

# join the data
df <- bind_cols(df1, df2) %>% 
  group_by(pie) %>% 
  mutate(pct = slices/sum(slices)*100) # pct for the pie - adds to 100
  
# graph
ggplot(df, aes(x="", y=pct, fill=labels)) + # pct used here so slices add to 100
  geom_bar(stat="identity", width=1) +
  coord_polar("y", start=0) +
  geom_text(aes(label = slices), position = position_stack(vjust=0.5)) +
  facet_wrap(~pie, ncol = 2) +
  theme_void() +
  theme(legend.position = "bottom")

Using an edited version of your data

> df
# A tibble: 12 x 4
# Groups:   pie [4]
     pie labels  slices   pct
   <int> <chr>    <dbl> <dbl>
 1     1 monthly     39    66
 2     1 daily        7    12
 3     1 weekly      13    22
 4     2 monthly     40    70
 5     2 daily        5     9
 6     2 weekly      12    21
 7     3 monthly     15    17
 8     3 daily       27    30
 9     3 weekly      47    53
10     4 monthly     58    54
11     4 daily       47    44
12     4 weekly       2     2