Because the extreme point of the energy function E(W)(W)(W is weight vector)is equal to zero point of the gradient,tracking the energy function extreme point can be converted into tracking its gradient function zero point.

• 因为能量函数E(W)(W是权重矢量)的极值点相当于梯度wE(W)的零点；因此；对能量函数极值点的跟踪可以转化为对其梯度函数零点的跟踪.