exm095_1.m

北京航空航天大学出版社张志涌、徐彦琴主编的matlab教程附带的mfile例程压缩包

%exm095_1.m
clear
clf
%图形数据的产生
zeta2=[0.2 0.4 0.6 0.8 1.0];
n=length(zeta2);
for k=1:n;
    Num{k,1}=1;
    Den{k,1}=[1 2*zeta2(k) 1];
end
S=tf(Num,Den);					%产生单输入多输出系统
t=(0:0.4:20)';					%时间采样点
[Y,x]=step(S,t);				%单输入多输出系统的响应
tt=t*ones(size(zeta2));		%为画彩带图，生成与函数值Y维数相同的时间矩阵。
%产生全窗轴位框，并隐去坐标轴
clf reset,H=axes('Position', [0, 0, 1, 1], 'Visible', 'off');
%产生包含多行字符串的元胞数组
str{1}='\fontname{隶书}二阶系统阶跃响应';									%<11>
str{2}='y(t) = 1 - \beta^{-1}e^{-\zetat}sin(\betat + \theta)';
str{3}=' ';str{4}='\fontname{隶书}其中：';
str{5}='\beta = (1 - \zeta^{2})^{0.5}';
str{6}='\theta = arctg(\beta/\zeta)';
str{7}='\zeta = .2, .4, .6, .8, 1';										%<15>
%使H句柄轴对象成为当前轴，然后注释多行文字。
set(gcf, 'CurrentAxes',H)													%<18>
text(0.01, 0.73, str, 'FontSize', 12)									%<19>
h1=axes('Position', [0.45, 0.45, 0.5, 0.5]);	%产生右半窗的轴位框
ribbon(tt,Y,0.4)										%在h1轴位框中画彩带图
%对X轴、Z轴重标刻度值
set(h1,'XTickLabelMode','manual','XTickLabel','0|0.4|0.8|1.2');%<23>
set(h1,'ZTickLabel','0|1.0|2.0');										%<24>
%低层指令标识轴名
set(get(h1,'XLabel'),'String','\zeta \rightarrow','Rotation',17.5)
set(get(h1,'YLabel'),'String','\leftarrow t','Rotation',-25)	%<27>
set(get(h1,'Zlabel'),'String','y \rightarrow')
h2=axes('Position',[0.03, 0.08, 0.27, 0.27]);%在左下角，产生小的轴位框。
plot(tt,Y)												%在h2轴对象上画二维图
%在右下方画系统方块框图
h3=axes('Position',[0.37,0.04,0.63,0.32]);	%设置画框图的轴位框
set(h3,'Xlim',[0,1.2],'Ylim',[0,0.5])			%设置轴的刻度范围
set(h3,'DataAspectRatio',[1 1 1])				%设置刻度比例
set(h3,'ColorOrder',[0,0,0])						%设置绘线的首选用色
set(h3,'Visible','off')								%隐去坐标轴
hh1=rectangle('Position',[0.5,0.2,0.4,0.2],'Curvature',[0,0]);
																%画方框				<37>
hh2=rectangle('Position',[0.2,0.26,0.08,0.08],'Curvature',[1,1]);
																%画圆框				<38>
xx1=0.05:0.01:0.2;xx2=0.28:0.02:0.5;
xx3=0.9:0.02:1.1;xx4=0.24:0.02:1;
yy5=0.1:0.02:0.26;yy6=0.1:0.02:0.3;
yy1=0.3*ones(size(xx1));yy2=0.3*ones(size(xx2));
yy3=0.3*ones(size(xx3));yy4=0.1*ones(size(xx4));
xx5=0.24*ones(size(yy5));xx6=ones(size(yy6));
line(xx1,yy1);line(xx2,yy2);line(xx3,yy3);line(xx4,yy4);
line(xx5,yy5);line(xx6,yy6)
line(0.17,0.3,'Marker','>','MarkerFaceColor','k')
line(0.47,0.3,'Marker','>','MarkerFaceColor','k')
line(1.1,0.3,'Marker','>','MarkerFaceColor','k')
line(0.24,0.23,'Marker','^','MarkerFaceColor','k')
line(0.17,0.35,'Marker','+')
text(0.27,0.23,'-')
text(0.05,0.35,'u(t)')
text(1,0.35,'y(t)')
text(0.6,0.26,'s{^2} + 2{\zeta}s');
xx7=0.56:0.02:0.84;yy7=0.3*ones(size(xx7));line(xx7,yy7)
text(0.68,0.35,'1')