[datatable-help] unique values in data.table

[Serdar Akin]

Hi all

I'm using data.table 1.10.5 and tried to the get unique values and 
keeping NA values

unique(

     data.table(    email = c(rep(NA,4), rep("david", 3), "frank"), nr = 
1:8)

      , by = 'email', na.rm = FALSE)

But this still removes the NA values.

Regards Serdar