This paper proposes an idea of data-driven predictive control for a linear
discrete-time system, that is, a tracking control algorithm based on input-
output data. Any traditional model of the plant, such as a transfer functio
n or a state equation, is not employed. The plant dynamics is represented b
y a rank constraint in an array whose elements are input-output data. The c
ontrol input for tracking an arbitrary reference signal is readily computed
using linear dependence of rows in the array. By refreshing the data., the
algorithm can adapt to the change of the plant dynamics.