This operator extracts or sets attributes for regular objects and S4 fields for S4 objects.

x %@% name

x 

Arguments

x

Object

name

Attribute name

Examples

# Unlike `@`, this operator extracts attributes for any kind of # objects: factor(1:3) %@% "levels"
#> [1] "1" "2" "3"
mtcars %@% class
#> [1] "data.frame"
mtcars %@% class <- NULL mtcars
#> $mpg #> [1] 21.0 21.0 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 17.8 16.4 17.3 15.2 10.4 #> [16] 10.4 14.7 32.4 30.4 33.9 21.5 15.5 15.2 13.3 19.2 27.3 26.0 30.4 15.8 19.7 #> [31] 15.0 21.4 #> #> $cyl #> [1] 6 6 4 6 8 6 8 4 4 6 6 8 8 8 8 8 8 4 4 4 4 8 8 8 8 4 4 4 8 6 8 4 #> #> $disp #> [1] 160.0 160.0 108.0 258.0 360.0 225.0 360.0 146.7 140.8 167.6 167.6 275.8 #> [13] 275.8 275.8 472.0 460.0 440.0 78.7 75.7 71.1 120.1 318.0 304.0 350.0 #> [25] 400.0 79.0 120.3 95.1 351.0 145.0 301.0 121.0 #> #> $hp #> [1] 110 110 93 110 175 105 245 62 95 123 123 180 180 180 205 215 230 66 52 #> [20] 65 97 150 150 245 175 66 91 113 264 175 335 109 #> #> $drat #> [1] 3.90 3.90 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 3.92 3.07 3.07 3.07 2.93 #> [16] 3.00 3.23 4.08 4.93 4.22 3.70 2.76 3.15 3.73 3.08 4.08 4.43 3.77 4.22 3.62 #> [31] 3.54 4.11 #> #> $wt #> [1] 2.620 2.875 2.320 3.215 3.440 3.460 3.570 3.190 3.150 3.440 3.440 4.070 #> [13] 3.730 3.780 5.250 5.424 5.345 2.200 1.615 1.835 2.465 3.520 3.435 3.840 #> [25] 3.845 1.935 2.140 1.513 3.170 2.770 3.570 2.780 #> #> $qsec #> [1] 16.46 17.02 18.61 19.44 17.02 20.22 15.84 20.00 22.90 18.30 18.90 17.40 #> [13] 17.60 18.00 17.98 17.82 17.42 19.47 18.52 19.90 20.01 16.87 17.30 15.41 #> [25] 17.05 18.90 16.70 16.90 14.50 15.50 14.60 18.60 #> #> $vs #> [1] 0 0 1 1 0 1 0 1 1 1 1 0 0 0 0 0 0 1 1 1 1 0 0 0 0 1 0 1 0 0 0 1 #> #> $am #> [1] 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 #> #> $gear #> [1] 4 4 4 3 3 3 3 4 4 4 4 3 3 3 3 3 3 4 4 4 3 3 3 3 3 4 5 5 5 5 5 4 #> #> $carb #> [1] 4 4 1 1 2 1 4 2 2 4 4 3 3 3 4 4 4 1 2 1 1 2 2 4 2 1 2 2 4 6 8 2 #> #> attr(,"row.names") #> [1] "Mazda RX4" "Mazda RX4 Wag" "Datsun 710" #> [4] "Hornet 4 Drive" "Hornet Sportabout" "Valiant" #> [7] "Duster 360" "Merc 240D" "Merc 230" #> [10] "Merc 280" "Merc 280C" "Merc 450SE" #> [13] "Merc 450SL" "Merc 450SLC" "Cadillac Fleetwood" #> [16] "Lincoln Continental" "Chrysler Imperial" "Fiat 128" #> [19] "Honda Civic" "Toyota Corolla" "Toyota Corona" #> [22] "Dodge Challenger" "AMC Javelin" "Camaro Z28" #> [25] "Pontiac Firebird" "Fiat X1-9" "Porsche 914-2" #> [28] "Lotus Europa" "Ford Pantera L" "Ferrari Dino" #> [31] "Maserati Bora" "Volvo 142E"
# It also works on S4 objects: .Person <- setClass("Person", slots = c(name = "character", species = "character")) fievel <- .Person(name = "Fievel", species = "mouse") fievel %@% name
#> [1] "Fievel"