中文说明：
例题运行步骤：在Matlab命令窗口将本章目录置于当前目录；在Matlab命令窗口的当前目录中打开本章目录中的M文件Exam.m；在Exam.m文件中，将待运行例题前的注释符号“ ”去掉，并保留其他例题前的注释符号“ ”；在命令窗口键入：Exam 并回车即可运行该例题。
English Description：
Example operation steps: put the directory of this chapter in the current directory in the matlab command window; In the current directory of matlab command window, open the m file exam. In the directory of this chapter m； In exam M file, remove the annotation symbol "" before the example to be run, and retain the annotation symbol "" before other examples; Type: exam in the command window and press enter to run the example