R语言中attr()函数
attr()函数允许你创建任意属性并将其与对象关联。
1、
> a <- 1:5 > b <- letters[1:5] > c <- LETTERS[1:5] > dat <- data.frame(a, b, c) > dat ## 测试数据框 a b c 1 1 a A 2 2 b B 3 3 c C 4 4 d D 5 5 e E > attributes(dat) ## 查看全部属性 $names [1] "a" "b" "c" $class [1] "data.frame" $row.names [1] 1 2 3 4 5 > attr(dat, "tag") ## 查看指定属性 NULL > attr(dat, "tag") <- "this is a test!" ## 添加新属性tag > attributes(dat) ## 查看全部属性 $names [1] "a" "b" "c" $class [1] "data.frame" $row.names [1] 1 2 3 4 5 $tag [1] "this is a test!" > attr(dat, "tag") ## 查看指定属性 [1] "this is a test!"
参考:https://blog.csdn.net/sinat_40586658/article/details/120442829