A packet switch apparatus including a plurality of connecting points, each being coupled to one of a plurality of data processing units, and apparatus for receiving a first packet including identification information of a first data processing unit via a first connecting point. The actuator is energized by pressured fluid, with a controlled pressured fluid source connected by an elongated flexible hose to the actuator so the pressured fluid source and a control can lie on the ground and only the actuator lies on the torso wrap. Merchant vectors represent specific merchants, and are aligned in a vector space as a function of the degree to which the merchants co-occur more or less frequently than expected.