duplicates
character string specifying how to handle duplicated
country or country-time observations (for the latter see timeVar
).
Can be set to none
to do nothing, message
to simply report
duplicates, drop
to report and drop duplicates, and return
to
return a data frame with only duplicated observations (see also
fromLast
).
timeVar
character string indicating the name of a time variable. For
example, country time series often have separate rows based on a year
variable. This is used solely to determine if there are duplicated
country-time values.