doUniqueCJ: Performs a Cross Join of Unique combinations
Description
This function makes use of CJ function of the data.table package to perform a
cross join. The function makes sure that the combinations are unique and removes NAs before
joining. doUniqueCJ is rather not used as a standalone function but inside computeShares.
Usage
doUniqueCJ(dt, cols)
Arguments
dt
data.table
cols
character vector that denotes names of relevant columns