第一个例子（用matlab实现归一化二阶系统）哈哈。。通过人家代码，了解了不少函数使用方法

%%得到归一化二阶系统的结缘响应曲线坐标图
clf reset%%clf是清除图像窗口中当前图像；reset重置所有对象设置，返回到最初默认状态
H=axes(\'unit\',\'normalized\',\'position\',[0,0,1,1],\'visible\',\'off\');%%figure左下角坐标为【0 0】，右上角[1 1],坐标不可见
set(gcf,\'currentaxes\',H);
str=\'\fontname{隶书}归一化二阶系统的阶跃响应曲线\';
text(0.12,0.93,str,\'fontsize\',13);
h_fig=get(H,\'parent\');
set(h_fig,\'unit\',\'normalized\',\'position\',[0.1,0.2,0.7,0.4]);
h_axes=axes(\'parent\',h_fig,\'unit\',\'normalized\',\'position\',[0.1,0.15,0.55,0.7],...
\'xlim\',[0 15],\'ylim\',[0 1.8],\'fontsize\',8);
%%在坐标右侧生成作解释的“静态文本”和可接受输入的“编辑框”
h_text=uicontrol(h_fig, \'style\' , \'text\' ,\'unit\' , \'normalized\' , \'position\' ,[0.67,0.73,0.25,0.14], ...
\'horizontal\' , \'left\' , \'string\' ,{ \' 输入阻尼比系数 \' , \'zeta =\' });
h_edit=uicontrol(h_fig, \'style\' , \'edit\' , \'unit\' , \'normalized\' , \'position\' ,[0.67,0.59,0.25,0.14], ...
\'horizontal\' , \'left\' , \'callback\' ,[\'z=str2num(get(gcbo,\'\'string\'\'));\' ,\'t=0:0.1:15;\' , \'for k=1:length(z);\' , ...

需要解释一下：    在edit中输入的是数字，用get得到输入的内容后，再把它转换为数字，然后赋值给z。  

                            gcbo :get current callback object
                            gcf:  get current figure
                            gca: get current axes
                            gcbf: get current callback figure
\'s2=tf(1,[1 2*z(k) 1]); \' ,\'y(:,k)=step(s2,t);\' ,\'plot(t,y(:,k));\' , \'if (length(z)>1) ,hold on,end,\' , \'end;\' ,\'hold off,\' ]);

其中tf是传递函数，step：产生阶跃函数
%%生成坐标方格控制按键
h_push1=uicontrol(h_fig, \'style\' , \'push\' , \'unit\' , \'normalized\' , \'position\' ,[0.67,0.37,0.12,0.15], \'string\' , \'grid on\' , \'callback\' , \'grid on\' );
h_push2=uicontrol(h_fig, \'style\' , \'push\' ,\'unit\' , \'normalized\' , \'position\' ,[0.67,0.15,0.12,0.15], \'string\' , \'grid off\' , \'callback\' , \'grid off\' );

其中：uicontrol的具体参数定义见http://blog.sina.com.cn/s/blog_6cb6157501015nb4.html

        get与set的具体参数见http://blog.163.com/xiaowshy@126/blog/static/691894272010324111925600/