Aspects of the invention include performing a stochastic update for a crossbar array by generating a set of stochastic pulses for a crossbar array, the crossbar array including a plurality of row wires and a plurality of column wires, the plurality of row wires including a first row wire and the plurality of column wires including a first column wire, wherein a three terminal device is coupled to the first row wire and the first column wire at a crosspoint of the first row wire and the first column wire, and wherein a resistivity of the three terminal device is modified responsive to a coincidence of pulses from the set of stochastic pulses at the crosspoint of the first row and the first column, and wherein at least one terminal in the three terminal device is floating.