r-在有序因子列中獲取所有NA

Question

它沒有在列中顯示more2或less2，而僅顯示為NA。 為什么沒有出現字符名稱呢？

careermore2 <- vector(mode="character",length=length(mlb$careeryrs))
"less2" <- careermore2[mlb$careeryrs<=2]
"more2" <- careermore2[mlb$careeryrs>=2]
No.seasons <-       factor(careermore2,levels=c("more2","less2"),exclude=NA,ordered=TRUE)
mlb2 <- cbind(mlb,No.seasons)
str(mlb2$No.seasons)
head(mlb2$No.seasons)
mlb2[mlb2$No.seasons=="more2",]

Answer 1

看一下careermore2我想你會錯誤地careermore2這些：

"less2" <- careermore2[mlb$careeryrs<=2]
"more2" <- careermore2[mlb$careeryrs>=2]

這將創建兩個對象。 您的意思是：

careermore2[mlb$careeryrs<=2] = "less2"
careermore2[mlb$careeryrs>=2] = "more2"

即在careermore2設置相應的值。 而且您可能想要<2或>2而不是都使用= ...