Internal constructor for projoint_qoi objects.
A projoint_qoi stores the specification of custom
quantities of interest (QOIs) for conjoint estimation.
Typically called by set_qoi rather than directly.
projoint_qoi(...)A list of QOI specifications with class "projoint_qoi".
Named elements specifying QOI details, such as:
structure: Analysis level ("profile_level" or "choice_level").
estimand: Quantity of interest ("mm" or "amce").
attribute_of_interest, levels_of_interest, etc.