在 R 中使用 ggplot2 向饼图图例添加值

Question

我用 R 中的 ggplot 创建了一个饼图，绘制了 7 家公司（A 到 G）的“金额”。

数据和代码如下：

# Data
data=data.frame('Company'=(c("A","B","C","D","E","F","G")),'Amount'=c(30,20,10,5,5,2,1))
data=data %>% mutate(Company= factor(x = Company, levels = Company)) %>% 
  mutate(prop = Amount / sum(data$Amount) ) %>%  mutate(ypos = cumsum(prop)- 0.5*prop )

# Pie chart
library(ggplot2)
ggplot(data, aes(x="", y=Amount, fill= Company) )+ 
  geom_bar(width = 1, stat = "identity") + coord_polar("y", start=0,direction = -1) + theme_void() +
  #geom_text(aes(label = percent(prop) ), size=3, position=position_stack(vjust=0.5)) +
  labs(x = NULL, y = NULL, fill = NULL) + scale_fill_brewer(palette="Blues", direction=-1) +
  geom_text(aes(label = percent(prop) ), size=3, position=position_stack(vjust=0.5)) 

但是，F 和 G 的标签相互堆叠，因此我们无法正确读取值。

我想将这些标签放在图例中，使图例显示为：A (41.1%) B (27.4%) C (13.7%) 等。

Answer 1

谢谢你，这行得通。

我只需要将 subdata$legend_labs 修改为一个因子变量，以保持图例中的顺序（即从最高金额到最低金额）。

Answer 2

这可以这样实现：

1. 通过粘贴公司名称和比例来添加新列
2. 在填充上映射这个新列

library(ggplot2)
library(dplyr)
library(scales)

# Data
data=data.frame('Company'=(c("A","B","C","D","E","F","G")),'Amount'=c(30,20,10,5,5,2,1))
data=data %>% mutate(Company= factor(x = Company, levels = Company)) %>% 
  mutate(prop = Amount / sum(data$Amount) ) %>%  
  mutate(ypos = cumsum(prop)- 0.5*prop) %>%
  mutate(legend_labs = paste0(Company, " (", percent(prop), ")"))

# Pie chart
library(ggplot2)
ggplot(data, aes(x="", y=Amount, fill= legend_labs) )+ 
  geom_bar(width = 1, stat = "identity") + 
  coord_polar("y", start=0, direction = -1) + 
  theme_void() +
  labs(x = NULL, y = NULL, fill = NULL) + 
  scale_fill_brewer(palette="Blues", direction=-1) +
  geom_text(aes(label = percent(prop) ), size=3, position=position_stack(vjust=0.5))