1

次のようなデータフレームがあります。

library(car)
mtcarsSubset <- car::some(mtcars)
mtcarsSubset <- mtcarsSubset[, c("mpg", "drat")]
mtcarsSubset$rows <- rownames(mtcarsSubset)

mtcarsSubset
                    mpg drat               rows
Datsun 710         22.8 3.85         Datsun 710
Duster 360         14.3 3.21         Duster 360
Merc 240D          24.4 3.69          Merc 240D
Merc 280           19.2 3.92           Merc 280
Merc 450SLC        15.2 3.07        Merc 450SLC
Cadillac Fleetwood 10.4 2.93 Cadillac Fleetwood
Toyota Corolla     33.9 4.22     Toyota Corolla
Toyota Corona      21.5 3.70      Toyota Corona
Dodge Challenger   15.5 2.76   Dodge Challenger
Ford Pantera L     15.8 4.22     Ford Pantera L

次のような 2 番目のデータフレームがあります。

mtcars <- mtcars[,c("gear", "carb")]
mtcars$new.variable <- NA
mtcars$rows <- rownames(mtcars)
                    gear carb new.variable                rows
Mazda RX4              4    4           NA           Mazda RX4
Mazda RX4 Wag          4    4           NA       Mazda RX4 Wag
Datsun 710             4    1           NA          Datsun 710
Hornet 4 Drive         3    1           NA      Hornet 4 Drive
Hornet Sportabout      3    2           NA   Hornet Sportabout
Valiant                3    1           NA             Valiant
Duster 360             3    4           NA          Duster 360
Merc 240D              4    2           NA           Merc 240D
Merc 230               4    2           NA            Merc 230
Merc 280               4    4           NA            Merc 280
Merc 280C              4    4           NA           Merc 280C
Merc 450SE             3    3           NA          Merc 450SE
Merc 450SL             3    3           NA          Merc 450SL
Merc 450SLC            3    3           NA         Merc 450SLC
Cadillac Fleetwood     3    4           NA  Cadillac Fleetwood
Lincoln Continental    3    4           NA Lincoln Continental
Chrysler Imperial      3    4           NA   Chrysler Imperial
Fiat 128               4    1           NA            Fiat 128
Honda Civic            4    2           NA         Honda Civic
Toyota Corolla         4    1           NA      Toyota Corolla
Toyota Corona          3    1           NA       Toyota Corona
Dodge Challenger       3    2           NA    Dodge Challenger
AMC Javelin            3    2           NA         AMC Javelin
Camaro Z28             3    4           NA          Camaro Z28
Pontiac Firebird       3    2           NA    Pontiac Firebird
Fiat X1-9              4    1           NA           Fiat X1-9
Porsche 914-2          5    2           NA       Porsche 914-2
Lotus Europa           5    2           NA        Lotus Europa
Ford Pantera L         5    4           NA      Ford Pantera L
Ferrari Dino           5    6           NA        Ferrari Dino
Maserati Bora          5    8           NA       Maserati Bora
Volvo 142E             4    2           NA          Volvo 142E

の がのrowにmtcarsSubset等しい場合、を転送したいと思います。この for ループでこれを達成できます。rowsmtcarsmpg

for (i in seq_along(mtcarsSubset$rows)) {

  x <- which(mtcars$rows  == mtcarsSubset$rows[i])
  mtcars$new.variable[x] <-  mtcarsSubset$mpg[i]

}

                    gear carb new.variable                rows
Mazda RX4              4    4           NA           Mazda RX4
Mazda RX4 Wag          4    4         21.0       Mazda RX4 Wag
Datsun 710             4    1         22.8          Datsun 710
Hornet 4 Drive         3    1           NA      Hornet 4 Drive
Hornet Sportabout      3    2           NA   Hornet Sportabout
Valiant                3    1         18.1             Valiant
Duster 360             3    4           NA          Duster 360
Merc 240D              4    2         24.4           Merc 240D
Merc 230               4    2           NA            Merc 230
Merc 280               4    4         19.2            Merc 280
Merc 280C              4    4           NA           Merc 280C
Merc 450SE             3    3           NA          Merc 450SE
Merc 450SL             3    3           NA          Merc 450SL
Merc 450SLC            3    3         15.2         Merc 450SLC
Cadillac Fleetwood     3    4           NA  Cadillac Fleetwood
Lincoln Continental    3    4           NA Lincoln Continental
Chrysler Imperial      3    4           NA   Chrysler Imperial
Fiat 128               4    1         32.4            Fiat 128
Honda Civic            4    2           NA         Honda Civic
Toyota Corolla         4    1           NA      Toyota Corolla
Toyota Corona          3    1           NA       Toyota Corona
Dodge Challenger       3    2           NA    Dodge Challenger
AMC Javelin            3    2         15.2         AMC Javelin
Camaro Z28             3    4         13.3          Camaro Z28
Pontiac Firebird       3    2           NA    Pontiac Firebird
Fiat X1-9              4    1         27.3           Fiat X1-9
Porsche 914-2          5    2           NA       Porsche 914-2
Lotus Europa           5    2           NA        Lotus Europa
Ford Pantera L         5    4           NA      Ford Pantera L
Ferrari Dino           5    6           NA        Ferrari Dino
Maserati Bora          5    8           NA       Maserati Bora
Volvo 142E             4    2           NA          Volvo 142E

私は特にからへplyrの転送を達成するための解決策を求めています。方法はわかりませんが、これを達成できるか、または達成できるかを考えています。これは可能ですか？mpgmtcarsSubsetmtcarsddply()ldplyplyr

4

2 に答える 2

3

plyrと組み合わせて具体的にこれを行う方法を次に示しifelse()ます。ddply()withを使用している場合、変数「new.variable」を初期化する必要はありませんtransform。

require(plyr)

ddply(mtcars, .(rows), transform, new.variable = ifelse(rows %in% mtcarsSubset$rows, mtcarsSubset$mpg[mtcarsSubset$rows == rows], NA) )

于 2013-07-16T22:22:26.167 に答える
0

おそらくあなたは探していmerge()ますか？

merge(mtcars, mtcarsSubset[ , "new.variable"], by="row.names", all.x=T)

于 2013-07-16T19:58:05.003 に答える