Two piecharts side by side in R

Question

I need two pie-charts side by side with the percentages of Covid19 cases, cured and death for two counties in Germany. One county left and the other one on the right.

So far my code looks like this:

RKI_COVID19 %>% 
  group_by(Landkreis) %>%
  summarise(fraction_active = (sum(AnzahlFall)-sum(AnzahlGenesen))/sum(AnzahlFall),
            fraction_cured = sum(AnzahlGenesen)/sum(AnzahlFall),
            fraction_death = sum(AnzahlTodesfall)/sum(AnzahlFall)) %>%
  subset(Landkreis == "SK Wolfsburg" | Landkreis == "SK Münster") %>%
  gather("Type", "Value", -Landkreis) %>%  # convert to long format
  ggplot(aes(Landkreis, Value, fill = Type)) +
  geom_col(position = "dodge") +
  geom_bar(stat = "identity", position = position_fill()) +
  geom_text(aes(label = round(Value, 2)), size = 3, position = position_fill(vjust = 0.5)) +
  facet_wrap(~Landkreis) +
  coord_polar("y")

after the subset() I have all values I am interestd in:

 Landkreis    fraction_active fraction_cured fraction_death
  <chr>                  <dbl>          <dbl>          <dbl>
1 SK Münster             0.108          0.892         0.0115
2 SK Wolfsburg           0.129          0.871         0.118

By using gather() I convert them in a long format and create two side by side barplots. This works great.

The problem occurs when using facet_wrap() and coord_polar() in the last two lines.

Then my pie-charts look like this:

One small and one donut pie-chart

Any ideas how to create two pie-charts with the same size?

The issue is that you map Landkreis on x. Try ggplot(aes(2, Value, fill = Type)) for equal size and + xlim(0.5, 2.5) to make it a donut. See here — stefan

Jack Jack · Accepted Answer · 2020-10-07T10:54:50

I've achieved this with a dummy variable which I've just named "n":

df = tribble(
  ~n, ~cat, ~act, ~cur, ~dea,
  1, "A", 0.1, 0.8, 0.1,
  1, "B", 0.05, 0.9, 0.05
) %>%
  pivot_longer(cols = c(act,cur,dea))

ggplot(df, aes(n, value, fill = name)) +
  geom_bar(stat = "identity", position = position_fill()) +
  geom_text(aes(label = round(value, 2)), size = 3, position = position_fill(vjust = 0.5)) +
  facet_wrap(~cat) +
  coord_polar("y")

This gives me:

Then you could remove the "n" axis using theme()

Two piecharts side by side in R

1 Answers