CODEWITHSUNDEEP
rdplyr
GreenManXY
GreenManXY

Reputation: 462

Replace NA by largest factor count of another column

Okey, after staring for hours at a dplyr cheat sheet I'm now finally giving up and asking my question here.

I have data in this form:

ID    Material    Supplier
1     a           01
2     b           02
3     NA          01
4     NA          02
4     a           02
4     b           02

Now, I want to replace the NAs with the most common material grouped by supplier. I'm using this code to count the most common materials and place the count in a data frame b but I want to do the replacement at the same time.

b <- a[which(!is.na(a$material)),] %>%
              group_by(supplier, material) %>%
              summarise(n = n()) %>%
              group_by(supplier) %>%
              filter(n == max(n))

Thanks in advance...

Upvotes: 2

Views: 89

Answers (1)

Lamia
Lamia

Reputation: 3875

You could do it using table within the dplyr function:

a %>%  
group_by(Supplier) %>%
mutate(Material=ifelse(is.na(Material),names(sort(table(Material),dec=T))[1],Material))

This returns:

    ID Material Supplier
  <int>    <chr>    <int>
1     1        a        1
2     2        b        2
3     3        a        1
4     4        b        2
5     4        a        2
6     4        b        2

Upvotes: 2

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