Quick question - How to convert all (or some: e.g. cols=1:5) columns at once (in one line) to another type (lets say integer), using dplyr.
A data to play with: df <- diamonds %>% slice(1:3) %>% select (5:10)
NB:
I know how to do it in data.table:
dt <- df %>% data.table;
cols=1:5
dt[ , (cols):=lapply(.SD, as.integer), .SDcol=cols]
You can use across to apply same function to multiple columns.
library(dplyr)
df %>% mutate(across(all_of(cols), as.integer))
#In old version we use `mutate_at`
#df %>% mutate_at(all_of(cols), as.integer)
# depth table price x y z
# <int> <int> <int> <int> <int> <dbl>
#1 61 55 326 3 3 2.43
#2 59 61 326 3 3 2.31
#3 56 65 327 4 4 2.31
Using all_of is not required but it is a good practice to use it when we use variables which are not present in the dataframe.
