我有一个包含产品信息(如ID,描述和类别(以及许多其他变量))的主数据框。使用R中另一个数据帧的变量完成数据帧
main.df <- structure(list(product.ID = 1:10,
description = c("abc...", "bcd...", "def...", "efg...", "fgh...",
"ghi...", "hij...", "ijk...", "jkl...", "klm..."),
category = c("a", "b", "c", "d", "e", "a", "b", "c", "d", "e")),
.Names = c("product.ID", "description", "category"),
row.names = c(NA, -10L), class = "data.frame")
然后,我有一个第二数据帧,它列出了类产品的每一个特定的类别属:
classes.df <- structure(list(category = c("a", "b", "c", "d", "e"),
classe = c("aaa", "bbb", "aaa", "ccc", "bbb")),
.Names = c("category", "classe"),
row.names = c(NA, -5L),
class = "data.frame")
“类别”的变量是什么“链接”的2个的数据帧。
我需要在main.df中添加一个变量来提及每行所属的产品类,但是我不知道如何去做。
考虑到我的实际main.df是4.5万行遍布90,000多个类别,我的实际classes.df有90,000行对应120个类,我该怎么做。 谢谢。
main.df结构
Classes ‘data.table’ and 'data.frame': 250000 obs. of 16 variables:
$ ID : int 4722 6988 9184 13224 13511 15938 19244 21162 23294 23793 ...
$ dataset : Factor w/ 2 levels "BA", "RB",..: 1 1 1 1 1 1 1 1 1 1 ...
$ prodID : num 429 429 429 429 429 429 429 429 429 429 ...
$ ProdName : chr "aaa" "aaa" "bbb" "ccc" "eee" ...
$ manufacID : num 1 1 1 1 1 1 1 1 1 1 ...
$ time : num 1271636264 1062977828 1218368958 1305424000 1284596323 ...
$ serial : chr "BA1" "BA1" "RB1" "RB7" ...
- attr(*, "sorted")= chr "serial"
- attr(*, ".internal.selfref")=<externalptr>
classes.df结构:
Classes ‘data.table’ and 'data.frame': 20565 obs. of 5 variables:
$ ID : int 652 1204 1252 1379 2334 2335 2336 2337 3186 3187 ...
$ mName : chr "XYZ" "EHD" "DLK" "TSH" ...
$ country: chr "Argentina" "USA" "UK" "Argentina" ...
$ serial : chr "RB7" "BA1" "RB97" "RB732" ...
- attr(*, ".internal.selfref")=<externalptr>
(出于保密原因,我不得不匿名化的名称)
如果我理解正确的话,你想用'serial'列作为链接变量。但是,有'ID'列也是一个常见变量。在预期的结果中,'main.df'有多少列? – akrun