Combine accross() condition with a col name condition

I have a dplyr chain with mutate like so:

df %>%
  mutate(across(where(is.factor), ~ as.numeric(levels(.))[.]))

I want to add a condition, in english ‘mutate where the col is factor AND where the column name does not equal bla’.

How can I combine these here?

>Solution :

You can combine where() with other tidyselect helpers e.g. matches or with other conditions, e.g. in your case you could use !COLUMN_NAME (Thx to @DarranTsai for pointing that out) to account for the column on which you don’t want to apply the function:

library(dplyr, warn = FALSE)

iris2 <- iris[c(1:5, 51:55, 101:105), ]
iris2$species2 <- iris2$Species

iris2 %>%
  mutate(across(where(is.factor) & !matches("^Species$"), ~ as.numeric(.)))
#>     Sepal.Length Sepal.Width Petal.Length Petal.Width    Species species2
#> 1            5.1         3.5          1.4         0.2     setosa        1
#> 2            4.9         3.0          1.4         0.2     setosa        1
#> 3            4.7         3.2          1.3         0.2     setosa        1
#> 4            4.6         3.1          1.5         0.2     setosa        1
#> 5            5.0         3.6          1.4         0.2     setosa        1
#> 51           7.0         3.2          4.7         1.4 versicolor        2
#> 52           6.4         3.2          4.5         1.5 versicolor        2
#> 53           6.9         3.1          4.9         1.5 versicolor        2
#> 54           5.5         2.3          4.0         1.3 versicolor        2
#> 55           6.5         2.8          4.6         1.5 versicolor        2
#> 101          6.3         3.3          6.0         2.5  virginica        3
#> 102          5.8         2.7          5.1         1.9  virginica        3
#> 103          7.1         3.0          5.9         2.1  virginica        3
#> 104          6.3         2.9          5.6         1.8  virginica        3
#> 105          6.5         3.0          5.8         2.2  virginica        3

Or using !:

iris2 %>%
  mutate(across(where(is.factor) & !Species, ~ as.numeric(.)))