行を結合するOREdplyr
関数。
表3-3 行の結合
関数 | 説明 |
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一致した列のxおよびyからすべての行の組合せを返します。 |
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例3-72 行の結合
2つの表を結合するため、join
関数は、同じ名前を持つ各表の列を選択するか、引数by
を使用して列を指定します。
MTCARS <- ore.push(mtcars) M1 <- filter(select(MTCARS, mpg, cyl, carb), carb < 6L) M2 <- filter(select(MTCARS, cyl, hp, carb), carb > 2L) names(inner_join(M1, M2)) nrow(left_join(M1, M2)) nrow(right_join(M1, M2)) nrow(full_join(M1, M2)) names(M2) <- c("cyl", "hp", "carb2") names(inner_join(M1, M2, by = c("cyl", carb="carb2"))) nrow(inner_join(M1, M2, by = c("cyl", carb="carb2"))) nrow(left_join(M1, M2, by = c("cyl", carb="carb2"))) nrow(right_join(M1, M2, by = c("cyl", carb="carb2"))) nrow(full_join(M1, M2, by = c("cyl", carb="carb2")))
この例のリスト
R> MTCARS <- ore.push(mtcars) R> M1 <- filter(select(MTCARS, mpg, cyl, carb), carb < 6L) R> M2 <- filter(select(MTCARS, cyl, hp, carb), carb > 2L) R> R> names(inner_join(M1, M2)) [1] "cyl" "carb" "mpg" "hp" R> nrow(left_join(M1, M2)) [1] 78 R> nrow(right_join(M1, M2)) [1] 63 R> nrow(full_join(M1, M2)) [1] 80 R> R> names(M2) <- c("cyl", "hp", "carb2") R> names(inner_join(M1, M2, by = c("cyl", carb="carb2"))) [1] "cyl" "carb" "mpg" "hp" R> nrow(inner_join(M1, M2, by = c("cyl", carb="carb2"))) [1] 61 R> nrow(left_join(M1, M2, by = c("cyl", carb="carb2"))) [1] 78 R> nrow(right_join(M1, M2, by = c("cyl", carb="carb2"))) [1] 63 R> nrow(full_join(M1, M2, by = c("cyl", carb="carb2"))) [1] 80