合并/加入R中的两个长df

Question

我有两个dataframes a和b我想结合

a <- data.frame(g=c("1","2","2","3","3","3","4","4","4","4"),h=c("1","1","2","1","2","3","1","2","3","4"))

b <- data.frame(g=c("1","2","3","3","3","4","4","4","4","4"),i=c("1","2","3","2","1","2","3","4","5","6"))

g代表分组变量,并h和i列我想合并/加入

> a
   g h
1  1 1
2  2 1
3  2 2
4  3 1
5  3 2
6  3 3
7  4 1
8  4 2
9  4 3
10 4 4

> b
   g i
1  1 1
2  2 2
3  3 3
4  3 2
5  3 1
6  4 2
7  4 3
8  4 4
9  4 5
10 4 6

a并且b应该在分组变量的级别上合并,g而相同的值h和它们i应该放在一起(与它们出现在h/ 中的顺序无关i),并且不应该将相同的值组合一次(不是所有可能的组合).

决赛df看起来像:

   g    h    i
1  1    1    1
2  2    1 <NA>
3  2    2    2
4  3    1    1
5  3    2    2
6  3    3    3
7  4    1 <NA>
8  4    2    2
9  4    3    3
10 4    4    4
11 4 <NA>    5
12 4 <NA>    6

我需要那个df来执行相关分析.

Answer 1

听起来像一个mergeon h==i,同时保留i,所以创建一个新的变量x来加入,并保持两边的连接结果(all=TRUE).给@Moody_Mudskipper一个大帽子:

merge(transform(a,x=h), transform(b,x=i), all=TRUE)

#   g x    h    i
#1  1 1    1    1
#2  2 1    1 <NA>
#3  2 2    2    2
#4  3 1    1    1
#5  3 2    2    2
#6  3 3    3    3
#7  4 1    1 <NA>
#8  4 2    2    2
#9  4 3    3    3
#10 4 4    4    4
#11 4 5 <NA>    5
#12 4 6 <NA>    6