def formula(individu, period, parameters): # If age_en_mois is known at the same day of another month, compute the new age_en_mois from it. holder = individu.get_holder('age_en_mois') start = period.start known_periods = holder.get_known_periods() for last_period in sorted(known_periods, reverse = True): last_start = last_period.start if last_start.day == start.day: last_array = holder.get_array(last_period) return last_array + ((start.year - last_start.year) * 12 + (start.month - last_start.month)) has_birth = individu.get_holder('date_naissance').get_known_periods() if not has_birth: has_age = bool(individu.get_holder('age').get_known_periods()) if has_age: return individu('age', period) * 12 date_naissance = individu('date_naissance', period) epsilon = timedelta64(1) return (datetime64(period.start) - date_naissance + epsilon).astype('timedelta64[M]')