中文说明：
在共梯度法中，只有当初值的选取靠近最优解时，迭代才会收敛。当远离时发散且当精度控制为0.1时可以实现，但设为0.01时就实现不了
English Description：
In the common gradient method, the iteration will converge only when the initial value is close to the optimal solution. Divergence can be achieved when it is far away and when the accuracy control is 0.1, but it cannot be achieved when it is set to 0.01 < br / >