Functions need to take data frame columns as arguments…
… but need to evaluate those names at the proper time and in proper context:
upon execution of the function
in the data (frame) environment
my_mean <-function(data, var1, var2) { dplyr::summarise(data, mean(var1 + var2))}my_mean(mtcars, cyl, am)#> Error in `dplyr::summarise()`:#> i In argument: `mean(var1 + var2)`.#> Caused by error:#> ! object 'cyl' not found