Question

我有两个数据框。第一个是工作：

Jobs <- data.frame(Company = c("A","B"), Name = c("Peter","Peter"), Job = c("CEO","Member of the Board"))

第二个是Media_Appearence：

Media_Appearence <- data.frame(Company = c("A","A","B","B","A","A","A","A"),Name = c("Peter","Peter","Peter","Peter","Peter","Peter","Peter","Peter"))

有没有办法，使用基本的R命令，在Media_Appearence上插入一个新列，使用匹配的参数填充它（检查前两列并返回匹配的作业）？所需的输出是：

Media_Appearence <- data.frame(Company = c("A","A","B","B","A","A","A","A"),Name = c("Peter","Peter","Peter","Peter","Peter","Peter","Peter","Peter"),Job= c("CEO","CEO","Member of the Board","Member of the Board","CEO","CEO","CEO","CEO"))

已经尝试合并，但结果很混乱。

由于

Answer 1

您想要做的通常称为“加入”，“合并”或“追加”数据。如果你不能这样做，R就不会是一种语言！

匹配的字段称为“密钥”。在这种情况下，R假设您的密钥为Company，因为它是他们共同的唯一字段。

Jobs <- data.frame(Company = c("A","B"), Name = c("Peter","Peter"), Job = c("CEO","Member of the Board"))

Media_Appearence <- data.frame(Company = c("A","A","B","B","A","A","A","A"),Name = c("Peter","Peter","Peter","Peter","Peter","Peter","Peter","Peter"))

merge(Media_Appearence, Jobs)

  Company  Name                 Job
1       A Peter                 CEO
2       A Peter                 CEO
3       A Peter                 CEO
4       A Peter                 CEO
5       A Peter                 CEO
6       A Peter                 CEO
7       B Peter Member of the Board
8       B Peter Member of the Board

您可能已经注意到您的数据已经为您排序了。它按默认键排序，在本例中为Company。

Answer 2

通过使用匹配，不会更改data.frame的原始顺序

Media_Appearence$Job=Jobs$Job[match(Media_Appearence$Company, Jobs$Company)]
Media_Appearence
  Company  Name                 Job
1       A Peter                 CEO
2       A Peter                 CEO
3       B Peter Member of the Board
4       B Peter Member of the Board
5       A Peter                 CEO
6       A Peter                 CEO
7       A Peter                 CEO
8       A Peter                 CEO

插入具有匹配值的列

2 个答案: