Add legend to ggplot2 bar plot

Question

note that this question differs from Add legend to ggplot2 line plot. This is a multiple bar plot and the answers provided for line plots dont apply.

How can I add a legend to the below?

library(tidyr);library(ggplot2)   
date <- 2001:2050
dat1 <- 1:50
dat2 <- 50:1
data <- tibble(date, dat1, dat2)
p2 <- ggplot(data, aes(x=date)) +
  geom_bar(aes(y=dat1, color = "orange"), stat = "identity", fill="orange")+
  geom_bar(aes(y=dat2,color = "blue"), stat = "identity", fill="blue")+
  ggtitle("dat") + 
  ylab("unit") 
p2

As you can see the default legends and bars are wrongly filled.

Does this answer your question? [Add legend to ggplot2 line plot](https://stackoverflow.com/questions/10349206/add-legend-to-ggplot2-line-plot) — Jonathan, Jun 30 '22 at 13:09
as mentioned, it doesnt. The legends are wrong if I try to follow these answers, reason why i post a new question specifically for *bar* charts — gaut, Jun 30 '22 at 13:10
it does not matter whether you have a bar or line chart; the same aesthetics apply, ggplot is build around this exact principle - also please don't post your question a second time if the first was flagged as an duplicate — Jonathan, Jun 30 '22 at 13:12
Please do not include commentary about the workings of the site in the question body itself. If you disagree with the actions taken, instead, post a question on [Meta StackOverflow](https://meta.stackoverflow.com/). — Ian Campbell, Jul 12 '22 at 20:09

score 0 · Accepted Answer · answered Jun 30 '22 at 13:13

library(tidyverse)

date <- 2001:2050
dat1 <- 1:50
dat2 <- 50:1
data <- tibble(date, dat1, dat2)

data %>%
  pivot_longer(c(dat1, dat2)) %>%
  ggplot(aes(date, value, fill = name)) +
  geom_col(position = position_identity())+
  scale_fill_manual(values = c("orange", "blue")) +
  ggtitle("dat") + 
  ylab("unit") +
  theme(axis.text.x = element_text(angle = 45, vjust = 0.5, hjust=1))

^{Created on 2022-06-30 by the reprex package (v2.0.1)}

Add legend to ggplot2 bar plot

1 Answers1