The $poststratify() method of an MRPModel object
runs Stan's standalone generated quantities and extracts posterior samples
for poststratified estimates. This method is called by the $poststratify()
method of a MRPWorkflow object and does not need to be called directly by users.
poststratify(interval = 0.95)A data.frame object containing the poststratified estimates and their corresponding uncertainty intervals.
Confidence interval (a numeric value between 0 and 1) or
standard deviation ("1sd" or "2sd") for the estimates (default is 0.95).