从列表R中删除特定变量

我想从R中的列表中删除预定义变量，例如：

vertex <- c("A","B","C","D")    
list_safe<-vertex

z<-sample(list_safe,1)

list_infected[z] <- z

list_safe_new<-list_safe[list_safe =! "z"]

---

vertex您定义了z，所以不应该在语句中添加“z”

vertex <- c("A","B","C","D")    
list_safe<-vertex

 z <-sample(list_safe,1)

 list_safe_new<-list_safe[list_safe != z]

顶点语法错误？你是说
list\u safe[list\u safe！=z]
你还没有定义
list\u infected
。