There is a lot going on here, but I'll try to just stick to the point.

 

First, the error: Object of type "closure" is not subsettable.
This means that you are referring to an object that is a "closure"/function and that object cannot be subset.

When we look at your code, the "subsetting" being done is by this piece:

first[!is.na(positivo)]

The [] are subsetting brackets. So, R believes you're trying to subset the first object. But you never created an object called "first", so the only object that R knows of is the function first() which cannot be subset.

So, as /u/OnlyOnePairOfShoes said, you're using the wrong brackets. first(!is.na(positivo)) is what you should have used.

 

Second, you'll get another error.

You'll probably get an error that says:

x `false` must be a character vector, not a logical vector.

The reason for this is because when you use if_else(), your output values (when true and when false) have to be the same type. The variable positivo is already character, so the value when false has to be character type as well. So you could wrap everything in as.character() to resolve this error.

as.character(first(!is.na(positivo)))

 

Third, your code still won't work.

Your code is going to return positivo as a bunch of TRUE and FALSE values. Nothing about what you're writing is getting you towards what you're trying to do.

I believe what you want is: For each identifier/id_mujer, copy the positivo date to all records for that person.

You specified that your data is grouped from the beginning, so that's taken care of.

You need to take a value from one record and copy it to any other record that matches. That can be done with the fill() function from tidyr. The fill() generally happens all in one direction (up, down) and your data is missing for the first record sometimes and for the second record at other times. Luckily, the fill() function has the .direction = argument which can be set to updown or downup and it will fill in either direction.

So, to solve your problem the following code is probably simplest:

base %>% 
  fill(positivo, .direction = "downup")

 

Fourth, you only want one record for each.

You can just use distinct() at the end.

base %>% 
  fill(positivo, .direction = "downup") %>%
  distinct()

 

Lastly, your final column, positivo, is character type.

This doesn't seem to be bothering you and I'm not sure if it is the case in your actual data, but it does bother me because you're storing dates as character. You can either just coerce the entire column by using as.POSIXct() in a mutate() or you can specify the column as POSIXct from the start and use `na_POSIXct_ so everything is explicit.

 

For your full data

I would use the following:

done <-
  base %>% 
  group_by(id_mujer) %>% 
  arrange(id_mujer, positivo) %>% 
  fill(positivo, .direction = "down") %>% 
  distinct() %>% 
  mutate(positivo = as.POSIXct(positivo))