匹配R中的值

Question

说，我有数据集

- env:
    - name: DB_ADDR
      value: postgres

如何显示x2变量中存在的值，但x1中没有变量？ 在我们的例子中，这是- env: - name: DB_ADDR value: postgres-keycloak 值

我想要的输出

mydat=structure(list(x1 = structure(c(2L, 3L, 4L, 5L, 1L), .Label = c("", 
"a", "b", "c", "d"), class = "factor"), x2 = structure(1:5, .Label = c("a", 
"b", "c", "d", "e"), class = "factor")), .Names = c("x1", "x2"
), class = "data.frame", row.names = c(NA, -5L))

x1 has values a,b,c,d
x2 has values a,b,c,d,e

如果该问题重复，请告诉我，我将其删除。

Answer 1

我们可以尝试

setdiff(mydat$x2,mydat$x1)
[1] "e"