如何在R中动态更改图表标题？

下面是一个使用

mtcars

将变量拆分为单独绘图的示例。我创建的是一个

vs

和

mpg

散点图，通过

cyl

分割数据集。首先创建一个空列表。然后我使用

lappy

循环遍历cyl（4,6,8）的值，然后

根据该值过滤数据。之后，我绘制了子集的散点图，并将其保存到空列表中

library(dplyr)
library(ggplot2)
gglist <- list()

gglist <- lapply(c(4,6,8), function(x){
    
    ggplot(filter(mtcars, cyl == x))+
        geom_point(aes(x=vs,y=mpg))+
        labs(title = "Relationship between vs and mpg based on the respective cyl")
})
gglist

各种图表标题的预期输出如下所示

#"Relationship between vs and mpg when cyl is 4"
#"Relationship between vs and mpg when cyl is 6"
#"Relationship between vs and mpg when cyl is 8"

 

您可以使用
paste
或
paste0
连接字符串，然后将其用作标题：

gglist <- lapply(c(4,6,8), function(x){
  
  ggplot(filter(mtcars, cyl == x))+
    geom_point(aes(x=vs,y=mpg))+
    labs(title = paste("Relationship between vs and mpg when cyl is ", x))
})
gglist

gglist
gglist <- lapply(c(4,6,8), function(x){
  
  ggplot(filter(mtcars, cyl == x))+
    geom_point(aes(x=vs,y=mpg))+
    labs(title = paste("Relationship between vs and mpg when cyl is ", x))
})
gglist