Hysteresis.

A function in which the algorithm for computing output changes at defined events or thresholds, such that output follows one path as input increases and another path as input decreases; Hysteresis can be formalized: (0) at initialization, select algorithm-0 (1).if event-1 occurs, switch to algorithm-1 (2) if event-2 occurs, switch to algorithm-2 ... (N) if event-n occurs, switch to algorithm-n Frequently in avionics, hysteresis prevents a test from oscillating near the transition point due to noise. Implementation is usually: (0) at initialization, set y = 0 (1) if x sub c + h/2 le x, then set y = 1 (2) if x sub c - h/2 lt x lt x sub c + h/2, then let y retain its value (3) if x le x sub c - h/2, then set y = 0