在这个箱图中我们可以看到平均值但是我们怎样才能在每个箱形图的每个平均值上都有图表上的数值?
ggplot(data=PlantGrowth, aes(x=group, y=weight, fill=group)) + geom_boxplot() +
stat_summary(fun.y=mean, colour="darkred", geom="point",
shape=18, size=3,show_guide = FALSE)
答案 0 :(得分:68)
首先,您可以使用aggregate
means <- aggregate(weight ~ group, PlantGrowth, mean)
此数据集可与geom_text
:
library(ggplot2)
ggplot(data=PlantGrowth, aes(x=group, y=weight, fill=group)) + geom_boxplot() +
stat_summary(fun.y=mean, colour="darkred", geom="point",
shape=18, size=3,show_guide = FALSE) +
geom_text(data = means, aes(label = weight, y = weight + 0.08))
此处,+ 0.08
用于将标签放在代表均值的点上方。
没有ggplot2
的替代版本:
means <- aggregate(weight ~ group, PlantGrowth, mean)
boxplot(weight ~ group, PlantGrowth)
points(1:3, means$weight, col = "red")
text(1:3, means$weight + 0.08, labels = means$weight)
答案 1 :(得分:21)
您可以使用stat_summary()
ggplot(data=PlantGrowth, aes(x=group, y=weight, fill=group))
+ geom_boxplot()
+ stat_summary(fun.y=mean, colour="darkred", geom="point", hape=18, size=3,show_guide = FALSE)
+ stat_summary(fun.y=mean, colour="red", geom="text", show_guide = FALSE,
vjust=-0.7, aes( label=round(..y.., digits=1)))
答案 2 :(得分:11)
您还可以使用stat_summary中的函数来计算平均值和放置文本的hjust参数,您需要一个额外的函数,但没有额外的数据框:
fun_mean <- function(x){
return(data.frame(y=mean(x),label=mean(x,na.rm=T)))}
ggplot(PlantGrowth,aes(x=group,y=weight)) +
geom_boxplot(aes(fill=group)) +
stat_summary(fun.y = mean, geom="point",colour="darkred", size=3) +
stat_summary(fun.data = fun_mean, geom="text", vjust=-0.7)
答案 3 :(得分:1)
我知道已有一个已接受的答案,但我希望在magrittr包的帮助下,以单一命令显示一种很酷的方法。
PlantGrowth %$% # open dataset and make colnames accessible with '$'
split(weight,group) %T>% # split by group and side-pipe it into boxplot
boxplot %>% # plot
lapply(mean) %>% # data from split can still be used thanks to side-pipe '%T>%'
unlist %T>% # convert to atomic and side-pipe it to points
points(pch=18) %>% # add points for means to the boxplot
text(x=.+0.06,labels=.) # use the values to print text
我将命令拆分为多行,以便我可以评论每个部分的作用,但也可以作为oneliner输入。您可以在我的gist中了解有关此内容的更多信息。