Figure 2

Changes in x _i , y _i in eight consecutive gradient descent steps. We set P(XY = 01) = P(XY = 10) = 0.49; and P(XY = 11) = P(XY = 00) = 0.01. Since x _i is larger than y _i in the beginning, it is hardly reduced. In contrast, y _i is reduced sharply to a negative value. The inferred states for measurement i are gene X is active gene Y is inactive.