1. An analog circuit for simultaneously computing the space-time average of a plurality of signals at inputs to an array comprising a plurality of nodes, each having capacitance connected to a source of fixed potential, a network of resistive connections between said plurality of nodes in said array, a separate integrator associated with each of said signal inputs, and means for injecting a current into each node of said array through said separate integrator associated therewith such that the magnitude of said current is an odd, monotonically increasing function of the potential difference between one of said signal inputs and said node.