In my character vector, each element represents a data object that exists in the environment.
my_objects <- c("mtcars", "LETTERS", "ToothGrowth")
Using rlang::syms() I can convert my_objects to a list of symbols.
library(rlang)
sym_objects <- syms(my_objects)
sym_objects
#> [[1]]
#> mtcars
#>
#> [[2]]
#> LETTERS
#>
#> [[3]]
#> ToothGrowth
My question: How can I evaluate sym_objects to get the data objects themselves?
Using eval() doesn't do what I want, as it simply returns the same as sym_objects.
eval(sym_objects)
#> [[1]]
#> mtcars
#>
#> [[2]]
#> LETTERS
#>
#> [[3]]
#> ToothGrowth
Desired output
Basically I want to do
whatever_evaluation_method(sym_objects)
To return:
#> [[1]]
#> mpg cyl disp hp drat wt qsec vs am gear carb
#> Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
#> Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4
#> Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
#> Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1
#> Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2
#> Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1
#> Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
#> Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
#> Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
#> Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4
#> Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4 4
#> Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3
#> Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3
#> Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3
#> Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4
#> Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4
#> Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4
#> Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1
#> Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2
#> Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1
#> Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1
#> Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2
#> AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2
#> Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4
#> Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2
#> Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1
#> Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2
#> Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2
#> Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4
#> Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5 6
#> Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8
#> Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2
#>
#> [[2]]
#> [1] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S"
#> [20] "T" "U" "V" "W" "X" "Y" "Z"
#>
#> [[3]]
#> len supp dose
#> 1 4.2 VC 0.5
#> 2 11.5 VC 0.5
#> 3 7.3 VC 0.5
#> 4 5.8 VC 0.5
#> 5 6.4 VC 0.5
#> 6 10.0 VC 0.5
#> 7 11.2 VC 0.5
#> 8 11.2 VC 0.5
#> 9 5.2 VC 0.5
#> 10 7.0 VC 0.5
#> 11 16.5 VC 1.0
#> 12 16.5 VC 1.0
#> 13 15.2 VC 1.0
#> 14 17.3 VC 1.0
#> 15 22.5 VC 1.0
#> 16 17.3 VC 1.0
#> 17 13.6 VC 1.0
#> 18 14.5 VC 1.0
#> 19 18.8 VC 1.0
#> 20 15.5 VC 1.0
#> 21 23.6 VC 2.0
#> 22 18.5 VC 2.0
#> 23 33.9 VC 2.0
#> 24 25.5 VC 2.0
#> 25 26.4 VC 2.0
#> 26 32.5 VC 2.0
#> 27 26.7 VC 2.0
#> 28 21.5 VC 2.0
#> 29 23.3 VC 2.0
#> 30 29.5 VC 2.0
#> 31 15.2 OJ 0.5
#> 32 21.5 OJ 0.5
#> 33 17.6 OJ 0.5
#> 34 9.7 OJ 0.5
#> 35 14.5 OJ 0.5
#> 36 10.0 OJ 0.5
#> 37 8.2 OJ 0.5
#> 38 9.4 OJ 0.5
#> 39 16.5 OJ 0.5
#> 40 9.7 OJ 0.5
#> 41 19.7 OJ 1.0
#> 42 23.3 OJ 1.0
#> 43 23.6 OJ 1.0
#> 44 26.4 OJ 1.0
#> 45 20.0 OJ 1.0
#> 46 25.2 OJ 1.0
#> 47 25.8 OJ 1.0
#> 48 21.2 OJ 1.0
#> 49 14.5 OJ 1.0
#> 50 27.3 OJ 1.0
#> 51 25.5 OJ 2.0
#> 52 26.4 OJ 2.0
#> 53 22.4 OJ 2.0
#> 54 24.5 OJ 2.0
#> 55 24.8 OJ 2.0
#> 56 30.9 OJ 2.0
#> 57 26.4 OJ 2.0
#> 58 27.3 OJ 2.0
#> 59 29.4 OJ 2.0
#> 60 23.0 OJ 2.0
(which is the same as list(mtcars, LETTERS, ToothGrowth) )
As you found, get() expects one string input to x=. To apply get() (or any function) over a vector or list, you can use lapply().
my_objects <- c("mtcars", "LETTERS", "ToothGrowth")
# This works
get(my_objects[1])
# Your expected result
lapply(my_objects, get)