如何将平均线添加到 R 中的分组密度图？

Question

我正在尝试绘制分组密度图并添加每个图的均值线；这是代码


data <- data.frame(
 Accuracy=abs(rnorm(140)),
Species=c(rep("A.All",20),rep("B. double",60),rep("C.single",60),
          rep("D.All",20),rep("E.double",60),rep("F.single",60)),

Modality=c(rep("All,w0",10),rep("double1,w0",10),rep("double2,w0",10),rep("double3,w0",10),
          rep("single1,w0",10),rep("single2,w0",10),rep("single3,w0",10),
          rep("All,w2",10),rep("double1,w2",10),rep("double2,w2",10),rep("double3,w2",10),
          rep("single1,w2",10),rep("single2,w2",10),rep("single3,w2",10))
)


p<-ggplot(data, aes(x=Accuracy, fill=Modality)) +
 geom_density(alpha=0.4)+
 facet_wrap(. ~ Species) +
 xlab("Accuracy") + ylab("Density")

library(plyr)
mu <- ddply(data, "Modality", summarise, grp.mean=mean(Accuracy))
head(mu)


# Add mean lines
a<-p+geom_vline(data=mu, aes(xintercept=grp.mean, color=Modality),
                linetype="dashed")+ xlab("Accuracy") + ylab("Density")

但是，根据输出图为

平均线绝对不正确，例如对于左上角的第一张图片，两个密度图应该有两条线，但是创建了几条线并为所有数字重复。

Answer 1

您可以同时指定 Species 和 Modality

`plyr`

dummy <- ddply(data, c("Species","Modality"), summarise, grp.mean=mean(Accuracy))

ggplot(data, aes(x=Accuracy, fill=Modality)) +
  geom_density(alpha=0.4)+
  facet_wrap(. ~ Species) +
  xlab("Accuracy") + ylab("Density") +
  geom_vline(data = dummy, aes(xintercept = grp.mean, color = Modality))

`dplyr`

library(dplyr)



dummy <- data %>%
  group_by(Species, Modality) %>%
  summarize(mean = mean(Accuracy))

ggplot(data, aes(x=Accuracy, fill=Modality)) +
  geom_density(alpha=0.4)+
  facet_wrap(. ~ Species) +
  xlab("Accuracy") + ylab("Density") +
  geom_vline(data = dummy, aes(xintercept = mean, color = Modality))

如何将平均线添加到 R 中的分组密度图？

How to add the mean line to grouped density plot in R?

r

ggplot2

mean

density-plot

`plyr`

`dplyr`