I was wondering if there might be a way to specify the name of a new variable used in mutate() (argument mutate_nm = "bb") inside the foo() function below?
library(tidyverse)
foo <- function(data = mtcars, mutate_nm, val = 12){
mutate(mutate_nm = val)
}
#==== EXAMPLE OF USE:
foo(mutate_nm = "bb") Doesn't produce a dataframe with a new column named `"bb"`
CodePudding user response：
We need to use := with !! or {{}}. Also, mutate by itself doesn't create any column i.e. need the data argument as well
foo <- function(data = mtcars, mutate_nm, val = 12){
data %>%
mutate({{mutate_nm}} := val)
#or use
#mutate(!! mutate_nm := val)
}
-testing
> foo(mtcars, "bb")
mpg cyl disp hp drat wt qsec vs am gear carb bb
Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4 12
Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4 12
Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1 12
Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1 12
Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2 12
Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1 12
Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4 12
Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2 12
Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2 12
Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4 12
Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4 4 12
Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3 12
Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3 12
Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3 12
Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4 12
Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4 12
Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4 12
Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1 12
Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2 12
Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1 12
Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1 12
Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2 12
AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2 12
Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4 12
Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2 12
Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1 12
Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2 12
Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2 12
Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4 12
Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5 6 12
Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8 12
Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2 12