R中每个字符变量的从属变量箱线图

我有一个dataframe，它有以下列：

   ks3score    ks4score      ethnic      gender    SECshort    hiquamum   singlepar       house 
  "numeric"   "numeric" "character" "character" "character" "character" "character" "character" 
        fsm      parasp    computer     tuition      pupasp    homework    attitude         asc 
"character" "character" "character" "character" "character" "character" "character" "character" 
        sen     truancy      absent     IDACI_n     FSMband 
"character" "character" "character"   "numeric" "character" 

我想为每个字符变量和ks4score绘制箱线图，现在我使用了下面的代码，但不够简洁：

boxplot(ks4score ~ ethnic, df)
boxplot(ks4score ~ gender, df)
...

只是想知道是否有办法改善它？谢谢。

您可以试试：

cols <- names(df)[sapply(df, is.character)]
all_plots <- lapply(cols, function(x) boxplot(reformulate(x, 'ks4score'), df))