r - ggplot2 coord_polar 在使用填充时保留顺序

Question

指定 fill aes 的论据导致饼图的顺序相反，因此中断/标签不再与饼图匹配。请参阅下面的示例和结果图。

df = data.frame(Var1 = letters[1:5], Var2 = c(6, 31, 34, 66, 77))    
df$Var1 = factor(df$Var1, levels = df$Var1, ordered = T)

# just fine, but no colors
ggplot(df, aes(x = 1,
               y = Var2)) +
  geom_bar(width = 1, stat = "identity") +
  coord_polar(theta = "y") +
  scale_fill_manual(values = c("red","green","yellow","black","white"),
                    guide_legend(title = "My_Title")) +
  scale_y_continuous(breaks = (cumsum(df$Var2) -
                                 df$Var2 / 2),
                     labels = df$Var1)

# reverse order appears
ggplot(df, aes(x = 1,
               y = Var2,
               fill = Var1)) +
  geom_bar(width = 1, stat = "identity") +
  coord_polar(theta = "y") +
  scale_fill_manual(values = c("red","green","yellow","black","white"),
                    guide_legend(title = "My_Title")) +
  scale_y_continuous(breaks = (cumsum(df$Var2) -
                                 df$Var2 / 2),
                     labels = df$Var1)

Answer 1

堆叠会以相反的因子顺序发生(根据 v2.2.0)，因此我们可以使用以下代码按原始顺序堆叠:

ggplot(df, aes(x = 1,
               y = Var2,
               fill = forcats::fct_rev(Var1))) +
    geom_bar(width = 1, stat = "identity", col = 1) +
    coord_polar(theta = "y") +
    scale_y_continuous(breaks = (cumsum(df$Var2) -
                                     df$Var2 / 2),
                       labels = df$Var1)

另外，您可以使用 geom_col而不是 geom_bar(stat = "identity") .