empirical_delay_data_format.RdEmpirical delay data format
An empirical_delays dataframe must contain (at least) two columns.
An 'event_date' column of type Date
and a 'report_delay' column of type numeric.
Each row represents the recording of a single delay between event and observation.
Typically, the 'event' here is the onset of symptoms of the disease of interest.
And the observation can be, for instance, case confirmation, hospital admission,
admission to an ICU, or death, depending on what the incidence data represents.
For a particular row, 'event_date' would then represent, for a single individual,
the date at which symptoms appeared. And 'report_delay' would represent the number
of time steps (as specified by time_step) until the observation was made
for this same individual.