1. chapter9.m为主程序，将该文件夹设置为MATLAB当前工作路径，运行即可。
2. data0～data9.mat为数字0～9对应的矩阵，data1_noisy和data2_noisy分别为数字1和数字2的加噪声矩阵。
3. waiji.m为外积法设计离散型Hopfield网络(具体见第10章介绍)。
4. 该程序在MATLAB2009a版本下测试通过，个别函数在低版本中不存在或者调用格式有所不同，参照对应版本中的帮助文档修改即可。(1. chapter9.m based program, the folder is set to MATLAB current working path, you can run.
2. Data0 to data9.mat is the corresponding matrix of number 0~9, and data1_noisy and data2_noisy are add noise matrixes of digital 1 and digital 2 respectively.
3. waiji.m design discrete Hopfield networks for external product (see the tenth chapter).
4., the program tested in the MATLAB2009a version, the individual functions in the lower version does not exist, or call the format is different, refer to the corresponding version of the help documentation can be modified.)