Apply a conditional function in a nested dataframe

[cereghetti]

Hi there. I have a nested dataframe like this:

df<-mpg %>% group_by(manufacturer) %>% nest()

And I have to apply this function to clean some values:

func<-function(drv,cty){
  values<-which(drv=="f"& cty<20)
  cty[values]<-0
  cty}

Only on these manufacturers

manufacturers_vector<-c("audi","chevrolet","jeep")

There is any way I can apply the function only if the manufacturer column in my df matches a value in manufacturers_vector?

[technocrat]

@cereghetti

df<-mpg %>% group_by(manufacturer) %>% nest()

to

df<-mpg %>% 
  filter(manufacturer %in% manufacturer_vector) %>%
  group_by(manufacturer) %>% nest()

[cereghetti]

Thank you.
In that way I would be discarding all other values (the ones not affected by my filter). There is any way to keep them?

[technocrat]

Reverse the filter to make a second df and then

dplyr::inner_join(df1,df2, key=“...”)

where ... is the common variable with unique values.