编写了简单的Widrow-Hoff学习算法，绘制学习速率在0.01、0.1和0.5时的误差变化趋势，迭代了5000次，另外一个描绘了三种情况的分解面-It is about the Widrow-Hoff learning algorithm.The algorithm sets three different learnging rate as 0.01,0.1 and 0.5.