當我填充ggplot2上的條形時，圖例消失

Question

我正在嘗試使用以下代碼繪制多層餅圖

df <- data.frame(a = c(4, 3, 3, 8, 1, 1, 10),
                 b = c("x", "x", "x", "y", "y", "y", "z"),
                 c = c("x1", "x2", "x3", "y1", "y2", "y3", "z1"))

ggplot(df, aes(x = b, y = a, fill = c))+
  geom_bar(stat = "identity",
           color = "black", 
           fill = c("yellow","blue","black","green","red","white","black"))+
  coord_polar(theta="y")

問題是，當我將填充變量添加到geom_bar中時，我失去了圖例，甚至根本無法添加圖例，嘗試按照某些建議添加scale_fill_manual() ，但它仍然對我不起作用，這是為什么發生了什么？

PS：是否可以刪除每個條/圓之間的空間？

Answer 1

您不需要第二個fill參數，即geom_bar中的geom_bar 。

library(ggplot2)
    df <- data.frame(a = c(4, 3, 3, 8, 1, 1, 10),
                     b = c("x", "x", "x", "y", "y", "y", "z"),
                     c = c("x1", "x2", "x3", "y1", "y2", "y3", "z1")
                     )

    ggplot(df, aes(x = b, y = a, fill = c))+
      geom_bar(stat = "identity",
               width=1,#set width to remove white space, b/c the default is 0.9
               color = "black",)+
      coord_polar(theta="y")+ #Note you don't need the scale_fill_manual below; if omitted, r uses the default palette
      scale_fill_manual(values = c("yellow","blue","black","green","red","white","black"))

    )

結果：