如何在 R 中动态更改图表标题?

How to change the chart title dynamically in R?

这是一个使用 mtcars 将变量拆分为单独绘图的示例。我创建的是 vsmpg 的散点图,将数据集拆分为 cyl。首先创建一个空列表。然后我使用 lapply 循环遍历 cyl (4,6,8) 的值,然后按该值 filter 循环数据。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

输出returns三个散点图,标题为"Relationship between vs and mpg based on the respective cyl"。但是我希望根据 cyl.

的唯一值动态更改每个散点图的标题
unique(mtcars$cyl)
#[1] 6 4 8

各种图表标题的预期输出如下。

#"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 pastepaste0 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