想了解R语言数据框合并(merge)的几种方式小结的相关内容吗，余醉 | dtminer在本文为您仔细讲解R语言数据框合并的相关知识和一些Code实例，欢迎阅读和指正，我们先划重点：R语言数据框合并,R语言合并数据框，下面大家一起来学习吧。
merge data frames (inner, outer, left, right)
数据
> df1 = data.frame(CustomerId = c(1:6), Product = c(rep("Toaster", 3), rep("Radio", 3)))
> df1
> CustomerId Product
1 1 Toaster
2 2 Toaster
3 3 Toaster
4 4 Radio
5 5 Radio
6 6 Radio
> df2 = data.frame(CustomerId = c(2, 4, 6), State = c(rep("Alabama", 2), rep("Ohio", 1)))
> df
> CustomerId State
1 2 Alabama
2 4 Alabama
3 6 Ohio
inner
> merge(x = df1, y = df2, by = "CustomerId", all = TRUE)
> CustomerId Product State
1 1 Toaster <NA>
2 2 Toaster Alabama
3 3 Toaster <NA>
4 4 Radio Alabama
5 5 Radio <NA>
6 6 Radio Ohio
left
> merge(x = df1, y = df2, by = "CustomerId", all.x = TRUE)
> CustomerId Product State
1 1 Toaster <NA>
2 2 Toaster Alabama
3 3 Toaster <NA>
4 4 Radio Alabama
5 5 Radio <NA>
6 6 Radio Ohio
right
> merge(x = df1, y = df2, by = "CustomerId", all.y = TRUE)
> CustomerId Product State
1 2 Toaster Alabama
2 4 Radio Alabama
3 6 Radio Ohio
outer
> merge(x = df1, y = df2, by = NULL)
> CustomerId.x Product CustomerId.y State
1 1 Toaster 2 Alabama
2 2 Toaster 2 Alabama
3 3 Toaster 2 Alabama
4 4 Radio 2 Alabama
5 5 Radio 2 Alabama
6 6 Radio 2 Alabama
7 1 Toaster 4 Alabama
8 2 Toaster 4 Alabama
9 3 Toaster 4 Alabama
10 4 Radio 4 Alabama
11 5 Radio 4 Alabama
12 6 Radio 4 Alabama
13 1 Toaster 6 Ohio
14 2 Toaster 6 Ohio
15 3 Toaster 6 Ohio
16 4 Radio 6 Ohio
17 5 Radio 6 Ohio
18 6 Radio 6 Ohio
