Q1:
sorting = function (table, column) {
# mtcars[order(mpg),]
return(table[order(column),])
}
sorting(mtcars, "mpg")
is equivalent to mtcars[order("mpg"),]
but not equals to the result I want to get which is mtcars[order(mpg),]
, how can I convert it from string to column name.
Q2:
similar:
library(tidyr)
comb = function(table, colNNN, arr, sep) {
return(unite(table, colNNN, all_of(arr), sep = sep))
}
and I do
comb(mtcars,"gearCarb",c("gear","carb"), "-")
and I got colNNN
as the final column name,
so how to convert symbol into a String?
Q1 can be solved without using non-standard evaluation using arrange_at
from dplyr
.
library(dplyr)
library(tidyr)
library(rlang)
sorting = function (table, column) {
return(table %>% arrange_at(column))
}
sorting(mtcars, "mpg")
# mpg cyl disp hp drat wt qsec vs am gear carb
#1 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4
#2 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4
#3 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4
#4 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
#5 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4
#6 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8
#...
For Q2 we can use {{}}
comb = function(table, colNNN, arr, sep) {
return(unite(table, {{colNNN}}, arr, sep = sep))
}
comb(mtcars,"gearCarb",c("gear","carb"), "-")
# mpg cyl disp hp drat wt qsec vs am gearCarb
#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
#...