R 内部結合（複数key）

【目的】　Rで複数キーの内部結合をする
【方法】　inner_join(df.x, df.y, by = c("key_1", "key_2"))
【補足】　library(dplyr)が必要

#テスト用データフレームを作成

v.x <- c(1,2,3,4)
v.x1 <- c("x","a","a","a")
v.x2 <- c("11","12","13","14")

v.y <- c(1,2,3,40)
v.y1 <- c("x","a","x","a")
v.y2 <- c("21","22","23","24")

df.x <- data.frame(id = v.x, name = v.x1, num = v.x2)
df.y <- data.frame(id = v.y, name = v.y1, num = v.y2)

> df.x
  id name num
1  1    x  11
2  2    a  12
3  3    a  13
4  4    a  14
> df.y
  id name num
1  1    x  21
2  2    a  22
3  3    x  23
4 40    a  24

#inner join
inner_join(df.x, df.y, by = c("id", "name")) 

> inner_join(df.x, df.y, by = c("id", "name"))
  id name num.x num.y
1  1    x    11    21
2  2    a    12    22

---他の結合---
R　内部結合（inner join）
R　内部結合（複数key）
R　外部結合(left join, right join)
R　完全外部結合(full join)
R　アンチ結合(anti join)

---dplyrとは？---
R　dplyrとはなんぞや？大規模データも簡単に処理？　～使い方～