如何在 R 中使用 mutate_at() 更改列？

Question

I want to replace all the instances of "" in the columns: VEHICLE.TYPE.CODE and CONTRIBUTING.FACTOR.VEHICLE .

My code is:

df %>% 
  select(VEHICLE.TYPE.CODE.1, VEHICLE.TYPE.CODE.2, 
         VEHICLE.TYPE.CODE.3, VEHICLE.TYPE.CODE.4, VEHICLE.TYPE.CODE.5, 
         CONTRIBUTING.FACTOR.VEHICLE.1, CONTRIBUTING.FACTOR.VEHICLE.2, 
         CONTRIBUTING.FACTOR.VEHICLE.3, CONTRIBUTING.FACTOR.VEHICLE.4, 
         CONTRIBUTING.FACTOR.VEHICLE.5) %>%
  mutate_at(vars(contains(" ")), funs("NONE")) 

However, this doesn't work. The "" are not replaced by "NONE" . Why does my code not work, and how can I fix my code to get "NONE" in my columns?

Thanks in advance!

Answer 1

We can use matches to match column names with a pattern and use replace to change values.

library(dplyr)

df %>% mutate_at(vars(matches('VEHICLE.TYPE.CODE|CONTRIBUTING.FACTOR.VEHICLE')), 
                     ~replace(., . == "", "NONE"))

Note that mutate_at is going to be replaced by across in future release of dplyr in which case syntax would change to:

df %>%
    mutate(across(matches('VEHICLE.TYPE.CODE|CONTRIBUTING.FACTOR.VEHICLE')),
           ~replace(., . == "", "NONE"))