geom_bar中的標籤錯誤

Question

我試圖在geom_bar中放置標籤，但是我不能。

我的代碼

df <- data.frame(
uni = rep(c("D","E","F","G","H"),3), 
Var1 = factor(c(rep("A",5),rep("B",5),rep("C",5))), 
Freq = c(53.6,50.0,48.5,50.0,56.2,23.2,18.5,27.7,20.0,14.3,23.2,31.5,23.8,30.0,29.6)) 


df$label = paste(round(df$Freq,0),"%", sep = "") 
ggplot(data = df, aes(x = uni, y = Freq, fill = Var1)) + 
geom_bar(stat = "identity",position = "fill", width = 1) + 
scale_fill_brewer(palette = 3) + geom_text(aes(y = Freq, label = label, position ="identity", face = "bold", size = 1), hjust=0.5, vjust=0.5) + 
xlab('') + 
ylab('') + 
labs(fill = '') + 
ggtitle('Example') + 
theme(axis.text.y = element_text(size=14,face="bold"), panel.background = element_blank(), plot.title = element_text(size = 20, colour = "black", face = "bold")) + 
guides(size=FALSE) 

Answer 1

通過使用ddply從plyr pacakage，我們可以創建基於累計總和一個新的變量來獲得每個標籤的正確位置：

library(plyr) 
df <- data.frame(
    uni = rep(c("D","E","F","G","H"),3), 
    Var1 = factor(c(rep("A",5),rep("B",5),rep("C",5))), 
    Freq = c(53.6,50.0,48.5,50.0,56.2,23.2,18.5,27.7,20.0,14.3,23.2,31.5,23.8,30.0,29.6)) 

df = ddply(df, .(uni), transform, labPosition = cumsum(Freq)-Freq/2) 

df$label = paste(round(df$Freq,0),"%", sep = "") 
ggplot(data = df, aes(x = uni, y = Freq, fill = Var1)) + 
    geom_bar(stat = "identity", width = 1) + 
    scale_fill_brewer(palette = 3) + 
    geom_text(aes(y = labPosition, label = label, position ="identity"), hjust=0.5, vjust=0.5, size = 1, face = "bold") + 
    xlab('') + 
    ylab('') + 
    labs(fill = '') + 
    ggtitle('Example') + 
    theme(axis.text.y = element_text(size=14,face="bold"), panel.background = element_blank(), plot.title = element_text(size = 20, colour = "black", face = "bold")) + 
    guides(size=FALSE) 

這會按組創建累積和的新變量，然後將頻率本身除以2減去中心它在該部分的中間。