Hi @paneves,
You didn't share your data so I demonstrated how to do this using some default data. This should do it for you. You can select the columns to sum over by naming each variable inside c(), or by using tidyselect selectors.
library(tidyverse)
mtcars %>%
rowwise() %>%
mutate(
# Can use tidyselect semantics inside c_across()
total = sum(c_across(c(disp, hp, wt)))
)
#> # A tibble: 32 x 12
#> # Rowwise:
#> mpg cyl disp hp drat wt qsec vs am gear carb total
#> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 21 6 160 110 3.9 2.62 16.5 0 1 4 4 273.
#> 2 21 6 160 110 3.9 2.88 17.0 0 1 4 4 273.
#> 3 22.8 4 108 93 3.85 2.32 18.6 1 1 4 1 203.
#> 4 21.4 6 258 110 3.08 3.22 19.4 1 0 3 1 371.
#> 5 18.7 8 360 175 3.15 3.44 17.0 0 0 3 2 538.
#> 6 18.1 6 225 105 2.76 3.46 20.2 1 0 3 1 333.
#> 7 14.3 8 360 245 3.21 3.57 15.8 0 0 3 4 609.
#> 8 24.4 4 147. 62 3.69 3.19 20 1 0 4 2 212.
#> 9 22.8 4 141. 95 3.92 3.15 22.9 1 0 4 2 239.
#> 10 19.2 6 168. 123 3.92 3.44 18.3 1 0 4 4 294.
#> # … with 22 more rows