r - Creating 3 barplots together

Question

I am trying to create 3 barplots in one plot using ggplot2. The 3 barplots share the same x axis values and thats how I want to group it, rather than putting the entire plots side by side like this:

Since the dataframe I am using is fairly large, I have put an idealised one below:

> d1rm.null
  Threat1_Cat Threat1 Threat2_Cat Threat2 Threat3_Cat Threat3
1           1     1.2           5     5.2           7     7.2
2           7     7.2           4     4.1           2     2.1
3           4     4.3           7     7.2           1     1.1
4           5     5.1           7     7.1           1     1.1
5           4     4.2           2     2.1           3     3.0

The scripts I have used to create one is below:

ggplot(data = d1rm.null, aes(x = Threat1_Cat, colour = Threat1)) +
    geom_bar() +
    labs(x = "Higher Threat Category", y="Frequency") +
    ggtitle("Threat 1 Distribution Before Any Exclusions") + 
    guides(colour=guide_legend(title="Higher Resolution Threat Category"))

Which has the output:

It's something similar to this that I am aiming the plot to look like, but with all 3 threats present.

Thank you!

Answer 1

I tried to reshape the data, but I couldn't find something to do it automatically, so I did it "by hand". There must be a better solution. Anyway, here is my code

T1 <- d1rm.null %>% 
  select(1:2) %>% 
  gather(Threat, Value, Threat1) %>% 
  rename(Cat = Threat1_Cat)

T2 <- d1rm.null %>% 
  select(3:4) %>% 
  gather(Threat, Value, Threat2) %>% 
  rename(Cat = Threat2_Cat)

T3 <- d1rm.null %>% 
  select(5:6) %>% 
  gather(Threat, Value, Threat3) %>% 
  rename(Cat = Threat3_Cat)

Total <- bind_rows(T1, T2, T3)
Total
# A tibble: 15 × 3
# Cat  Threat Value
# <dbl>   <chr> <dbl>
#   1      1 Threat1   1.2
# 2      7 Threat1   7.2
# 3      4 Threat1   4.3
# 4      5 Threat1   5.1
# 5      4 Threat1   4.2
# 6      5 Threat2   5.2
# 7      4 Threat2   4.1
# 8      7 Threat2   7.2
# 9      7 Threat2   7.1
# 10     2 Threat2   2.1
# 11     7 Threat3   7.2
# 12     2 Threat3   2.1
# 13     1 Threat3   1.1
# 14     1 Threat3   1.1
# 15     3 Threat3   3.0

And then the graph, if I understand what you want.

ggplot(data = Total, aes(x = Cat, fill = Threat)) +
  geom_bar(position = "dodge")