ggplot图例标题修改问题：如何将图例标题从name改为space？

数据集与原代码 #

数据集 #

生成数据集的R代码 #

data <- data.frame(
  stringsAsFactors = FALSE,
  Region = c("North", "South", "West", "East"),
  Greenspace = c(30,50,15,10),
  Bluespace = c(5,10,2,1)
)

原绘图代码 #

data %>% 
  pivot_longer(cols = Greenspace:Bluespace) %>% 
  ggplot(aes(x = Region, y = value, fill = name)) + 
  geom_col(position = 'dodge') + 
  ggtitle("Contrast between 4 different region areas for Greenspace and Bluespace") + 
  xlab("Region") + 
  ylab("percentage")+ 
  scale_fill_manual(values=c("blue", "dark green"))

问题 #

想将图例标题改为“space”，但直接把aes中的fill = name改成fill = space时，会出现“找不到space”的错误。

解决方法 #

有两种简单的解决方式：

方式1：修改pivot_longer的列名 #

在pivot_longer时直接把生成的分类列命名为space，后续aes里直接用fill = space就不会报错，图例标题自动变为“space”：

data %>% 
  pivot_longer(cols = Greenspace:Bluespace, names_to = "space") %>% 
  ggplot(aes(x = Region, y = value, fill = space)) + 
  geom_col(position = 'dodge') + 
  ggtitle("Contrast between 4 different region areas for Greenspace and Bluespace") + 
  xlab("Region") + 
  ylab("percentage")+ 
  scale_fill_manual(values=c("blue", "dark green"))

方式2：用labs()修改图例标题 #

保持原pivot_longer代码不变，通过labs(fill = "space")指定图例标题，无需修改aes里的fill参数：

data %>% 
  pivot_longer(cols = Greenspace:Bluespace) %>% 
  ggplot(aes(x = Region, y = value, fill = name)) + 
  geom_col(position = 'dodge') + 
  ggtitle("Contrast between 4 different region areas for Greenspace and Bluespace") + 
  xlab("Region") + 
  ylab("percentage")+ 
  scale_fill_manual(values=c("blue", "dark green")) +
  labs(fill = "space")  # 新增该行修改图例标题

内容的提问来源于stack exchange，提问作者user19729000