ggplot2作分组箱线图并添加均值点连线及显著性程度标注

下面这个箱线图由两部分组成，左边是1,2两组A,B,C,D,E属性的箱线图，右边是1,2两组整体水平的箱线图，下面通过R语言的ggplot2包从头绘制类似这种箱线图及其各个组的均值点连线和显著性程度标注。

载入所小的包并生成数据：

rm(list=ls())
library(data.table)
library(ggplot2)
library(ggsignif)
Group1<-data.frame(A=runif(100,15,90),B=rnorm(100,30,3),C=runif(100,30,60),D=rexp(100,0.1),E=rpois(100,10),group=1)
Group2<-data.frame(A=runif(100,0,100),B=rnorm(100,50,2),C=runif(100,40,70),D=rexp(100,0.3),E=rpois(100,20),group=2)
# 整合数据到一个数据框：
b<-rbind(Group1,Group2)

```R
数据如下，一共有A,B,C,D,E5个属性，分1,2两个组。
![](https:https://img.haomeiwen.com/i903467/9e7001b20f8e3e9f.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

将数据框宽格式变长格式方便制图：
```R
b<-melt(b,id.vars = c("group"))
b$group<-as.factor(b$group)

变成长格式的数据：

由于要做每个箱线图的均值点及均值连线，需要获得每个组每个属性的均值，并且定义每个组每个属性的X坐标为固定值。

# group1的mean:
c<-copy(b)
setDF(c)
c1<-tapply(c[c$group==1,"value"],c[c$group==1,"variable"],mean)
c2<-tapply(c[c$group==2,"value"],c[c$group==2,"variable"],mean)
c3<-rbind(data.frame(variable=names(c1),value=c1,group=1),data.frame(variable=names(c2),value=c2,group=2))

c3$group<-as.factor(c3$group)
# 分别计算两组均值，用来画折线图：
c3$variable2<-NA
c3[c3$group==1&c3$variable=="A","variable2"]<-0.795
c3[c3$group==1&c3$variable=="B","variable2"]<-1.795
c3[c3$group==1&c3$variable=="C","variable2"]<-2.795
c3[c3$group==1&c3$variable=="D","variable2"]<-3.795
c3[c3$group==1&c3$variable=="E","variable2"]<-4.795

c3[c3$group==2&c3$variable=="A","variable2"]<-1.185
c3[c3$group==2&c3$variable=="B","variable2"]<-2.185
c3[c3$group==2&c3$variable=="C","variable2"]<-3.185
c3[c3$group==2&c3$variable=="D","variable2"]<-4.185
c3[c3$group==2&c3$variable=="E","variable2"]<-5.185

用来做均值点和连线的数据如下：

开始做两组每个属性的箱线图：

p1<-ggplot(b)+
  geom_boxplot(aes(x=variable,y=value,fill=group),width=0.6,position = position_dodge(0.8),outlier.size = 0,outlier.color = "white")+
  scale_fill_manual(values = c("red", "blue"),breaks=c("1","2"),labels=c("Group 1","Group 2"))+
  geom_point(data=c3,aes(x=variable2,y=value,color=group),shape=15,size=1)+
  geom_line(data=c3,aes(x=variable2,y=value,color=group),size=1,linetype = "dotted")+
  # geom_smooth(data=c3,aes(x=variable2,y=value,color=group),size=1,linetype = "dashed")+
  # stat_summary(fun.y = mean, geom = "errorbar", aes(x=variable,y=value,ymax = ..y.., ymin = ..y..,color=group),width = .75, linetype = "dashed")
  xlab("")+
  ylab("")+
  scale_y_continuous(limits = c(0,110),breaks=seq(0,110,5)) +
  geom_signif(stat="identity",
              data=data.frame(x=c(0.795,1.795,2.795,3.795,4.795), xend=c(1.185, 2.185,3.185,4.185,5.185),
                              y=c(106,66,70,30,35), annotation=c("***", " *** ","  ***  ","    **    ","*")),
              aes(x=x,xend=xend, y=y, yend=y, annotation=annotation)) +
  theme_bw()+
  theme(
    legend.position = "top",
    legend.background=element_blank(),
    legend.key = element_blank(),
    legend.margin=margin(0,0,0,0,"mm"),
    axis.text.x=element_text(size=rel(1.1),face="bold"),
    axis.line.x = element_line(size = 0.5, colour = "black"),
    axis.line.y = element_line(size = 0.5, colour = "black"),
    legend.text=element_text(size=rel(1.1)),
    legend.title=element_blank(),
    panel.border = element_blank(),
    panel.grid = element_blank()
  )+
  guides(color=FALSE)
p1

生成图像如下：

然后做两组整体水平的箱线图：

p2<-ggplot(b)+
  geom_boxplot(aes(x=group,y=value,fill=group),width=0.8,position=position_dodge(1))+
  stat_summary(fun.y = mean, geom = "point", aes(x=group,y=value,color=group),shape=15)+
  scale_fill_manual(values = c("red", "blue"),breaks=c("1","2"),labels=c("Group 1","Group 2"))+
  scale_x_discrete(breaks=c("1","2"),labels=c("Group 1","Group 2"))+
  scale_y_continuous(limits = c(0,110),breaks=seq(0,110,5)) +
  geom_signif(stat="identity",
              data=data.frame(x=c(1), xend=c(2),
                              y=c(106), annotation=c("**")),
              aes(x=x,xend=xend, y=y, yend=y, annotation=annotation))+
  theme_bw()+
  theme(
    legend.position = "top",
    legend.background=element_blank(),
    legend.key = element_blank(),
    legend.margin=margin(0,0,0,0,"mm"),
    axis.text.x=element_text(size=rel(1.1),face="bold"),
    axis.line.x = element_line(size = 0.5, colour = "black"),
    axis.line.y = element_blank(),
    axis.ticks.y = element_blank(),
    axis.text.y = element_blank(),
    axis.title = element_blank(),
    legend.text=element_text(size=rel(1.1)),
    legend.title=element_blank(),
    plot.margin = margin(11.5,0,7,0,"mm"),
    panel.border = element_blank(),
    panel.grid = element_blank()
  )+
  guides(fill=F,color=F)
p2

最后合并两个图像：

# 如果没有安装则install.packages("gridExtra")
library(gridExtra)
# 合并两个图：
grid.arrange(p1, p2, nrow=1, ncol=2,widths=c(3.5,1),heights=c(4))

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