c_across() works inside of mutate_rowwise(). It uses tidyselect so
you can easily select multiple variables.
c_across.(cols = everything())Columns to transform.
df <- data.table(x = runif(6), y = runif(6), z = runif(6))
df %>%
mutate_rowwise(row_mean = mean(c_across(x:z)))
#> # A tidytable: 6 × 4
#> x y z row_mean
#> <dbl> <dbl> <dbl> <dbl>
#> 1 0.590 0.192 0.117 0.300
#> 2 0.0307 0.187 0.745 0.321
#> 3 0.676 0.842 0.751 0.756
#> 4 0.277 0.681 0.0463 0.335
#> 5 0.792 0.660 0.496 0.649
#> 6 0.930 0.471 0.0846 0.495