Changing the fill order in a clustered geom_col?

Question

I'm trying to manually re-order the bar clusters within my plot. This is the entire relevant dataset:

Season  Set Density
Summer  Full set    0.020065
Summer  Set 2   0.017713
Summer  Set 3   0.015170
Summer  Set 4   0.018816
Autumn  Full set    0.009459
Autumn  Set 2   0.007937
Autumn  Set 3   0.008498
Autumn  Set 4   0.011544
Winter  Full set    0.017685
Winter  Set 2   0.015451
Winter  Set 3   0.013294
Winter  Set 4   0.016717
Spring  Full set    0.021445
Spring  Set 2   0.018672
Spring  Set 3   0.016526
Spring  Set 4   0.019715

And the ggplot code:

plot <-
  ggplot(arrange(data1day, Season), aes(x = Set, y = 100 * Density, fill = Season)) +
  geom_col(position = 'dodge', color = 'black') +
  theme_classic() +
  labs(x = "Subset of sites surveyed", y = "Density (%)") +
  scale_x_discrete(limits = c("Full set", "Set 2", "Set 3", "Set 4")) +
  scale_fill_brewer(limits = c("Summer", "Autumn", "Winter", "Spring"), palette = "Set2") +
  theme(text = element_text(size = 14, family = "serif", colour = "black")) +
  theme(axis.text.x = element_text(colour = "black")) +
  theme(axis.text.y = element_text(colour = "black"))

The legend lists the seasons in the correct order (Summer, Autumn, Winter, Spring) and the colours and bars correspond to the correct data (with Autumn always being lowest) but the bars don't match the order of the legend. I can't seem to find how to do this anywhere else.

Answer 1

You can use fct_relevel

library(dplyr)

data1day %>%
  arrange(Season) %>%
  mutate(Season = as.factor(Season),
         Season = fct_relevel(Season, "Summer", "Autumn", "Winter", "Spring")) %>%
  ggplot( aes(x = Set, y = 100 * Density, fill = Season)) +
  geom_col(position = 'dodge', color = 'black') +
  theme_classic() +
  labs(x = "Subset of sites surveyed", y = "Density (%)") +
  scale_x_discrete(limits = c("Full set", "Set 2", "Set 3", "Set 4")) +
  scale_fill_brewer(limits = c("Summer", "Autumn", "Winter", "Spring"), palette = "Set2") +
  theme(text = element_text(size = 14, family = "serif", colour = "black")) +
  theme(axis.text.x = element_text(colour = "black")) +
  theme(axis.text.y = element_text(colour = "black"))