如何在ggplot中更正饼图中的标签位置。还告诉我如何制作3D饼图

Question

我的数据集中的值之一为零，我认为因此无法正确调整饼图中的标签。

#Providing you all a sample dataset 
Averages <- data.frame(Parameters = c("Cars","Motorbike","Bicycle","Airplane","Ships"), Values = c(15.00,2.81,50.84,51.86,0.00))



mycols <- c("#0073C2FF", "#EFC000FF", "#868686FF", "#CD534CFF","#FF9999")
duty_cycle_pie <- Averages %>% ggplot(aes(x = "", y = Values, fill = Parameters)) +
  geom_bar(width = 1, stat = "identity", color = "white") +
  coord_polar("y", start = 0)+
  geom_text(aes(y = cumsum(Values) - 0.7*Values,label = round(Values*100/sum(Values),2)), color = "white")+
  scale_fill_manual(values = mycols)

标签放置不正确。请告诉我如何获得3D饼图。

Answer 1

欢迎来到stackoverflow。我很乐意为您提供帮助，但是，我必须指出，饼图具有很高的争议性，而3D饼图被认为是不良做法。

https://www.darkhorseanalytics.com/blog/salvaging-the-pie https://en.wikipedia.org/wiki/Misleading_graph#3D_Pie_chart_slice_perspective

此外，如果变量的名称反映了您的实际数据集（Averages），则不适合使用饼图，因为这些部分似乎并未描述整体的一部分。例如：Bicycle的平均值为50.84，Airplane的平均值为51.86。这些结果分别占43％和42％令人困惑；条形图会更容易理解。

尽管如此，您关于布局的问题的答案可以通过position_stack()来解决。

library(tidyverse)

Averages <- 
  data.frame(
    Parameters = c("Cars","Motorbike","Bicycle","Airplane","Ships"), 
    Values = c(15.00,2.81,50.84,51.86,0.00)
  ) %>% 
  mutate(
    # this will ensure the slices go biggest to smallest (a best practice)
    Parameters = fct_reorder(Parameters, Values),
    label = round(Values/sum(Values) * 100, 2)
  )

mycols <- c("#0073C2FF", "#EFC000FF", "#868686FF", "#CD534CFF","#FF9999")

Averages %>% 
  ggplot(aes(x = "", y = Values, fill = Parameters)) +
  geom_bar(width = 1, stat = "identity", color = "white") +
  coord_polar("y", start = 0) +
  geom_text(
    aes(y = Values, label = label), 
    color = "black", 
    position = position_stack(vjust = 0.5)
  ) +
  scale_fill_manual(values = mycols) 

要将棋子移到饼图的外部，您可以查看ggrepel https://stackoverflow.com/a/44438500/4650934

就我之前的观点而言，我可以尝试使用类似的方法代替饼图：

ggplot(Averages, aes(Parameters, Values)) +
  geom_col(aes(y = 100), fill = "grey70") +
  geom_col(fill = "navyblue") +
  coord_flip()