I want to create a function that takes a grouping argument. Which can be a single or multiple variables. I want it to look like this:
wanted <- function(data, groups, other_params){
data %>% group_by( {{groups}} ) %>% count()
}
This work only when a single group is given but breaks when there are multiple groups. I know it's possible to use the following with ellipsis ...
(But I want the syntax groups = something
):
not_wanted <- function(data, ..., other_params){
data %>% group_by( ... ) %>% count()
}
Here is the entire code:
library(dplyr)
library(magrittr)
iris$group2 <- rep(1:5, 30)
wanted <- function(data, groups, other_params){
data %>% group_by( {{groups}} ) %>% count()
}
not_wanted <- function(data, ..., other_params){
data %>% group_by( ... ) %>% count()
}
# works
wanted(iris, groups = Species )
not_wanted(iris, Species, group2)
# doesn't work
wanted(iris, groups = vars(Species, group2) )
wanted(iris, groups = c(Species, group2) )
wanted(iris, groups = vars("Species", "group2") )
# Error: Column `vars(Species, group2)` must be length 150 (the number of rows) or one, not 2
You guys are over complicating things, this works just fine:
library(tidyverse)
wanted <- function(data, groups){
data %>% count(!!!groups)
}
mtcars %>% wanted(groups = vars(mpg,disp,hp))
# A tibble: 31 x 4
mpg disp hp n
<dbl> <dbl> <dbl> <int>
1 10.4 460 215 1
2 10.4 472 205 1
3 13.3 350 245 1
4 14.3 360 245 1
5 14.7 440 230 1
6 15 301 335 1
7 15.2 276. 180 1
8 15.2 304 150 1
9 15.5 318 150 1
10 15.8 351 264 1
# … with 21 more rows