在R中找到缺少的行

问题描述

我有以下list和data.frame。

 rows_i_need = c(letters)
 df1 = data.frame(a=c("a","b","c","e","f","g","i","j","k"),b=rnorm(9,6,2),c=rnorm(9,12,3.5),d=rnorm(9,8,3)
      )

如何创建“缺少行”的新列表，以及输出列表：

 missing_rows = c("d","h","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z")

解决方法

您可以使用此...

missing_rows = rows_i_need [！rows_i_need％in％df1 $ a]

,

我建议使用match()的方法：

rows_i_need[-match(df1$a,rows_i_need)]

输出：

[1] "d" "h" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" "x" "y" "z"