vib.m

阻尼振动的matlab程序(matlab程序)

% 阻尼振动 
close all 
rectangle('position',[12,8,2,0.3],'FaceColor',[0.1,0.3,0.4]); 
axis([0,15,-1,10]);hold on 
plot([13,13],[7,8],'r','linewidth',2); 
y=2:.2:7;M=length(y); 
x=12+mod(1:M,2)*2; 
x(1)=13;x(end-3:end)=13; 
D=plot(x,y);          % 句柄[弹簧] 
% Author's email:[e-mail]  
C=0:.1:2*pi;r=0.3; 
t1=r*sin(C); 
F1=fill(13+r*cos(C),2+t1,'r');  % 句柄[球] 
set(gca,'ytick',[0:2:9]); 
set(gca,'yticklabels',num2str([-1:3]')); 
plot([0,15],[2,2],'black'); 
H1=plot([0,13],[2,2],'g');  % 句柄[绿线] 
Q=plot(0,2.5,'color','r');  % 运动曲线; 
td=[];yd=[]; 
T=0; 
text(2,8,'damp osillation','fontsize',24); 
set(gcf,'doublebuffer','on'); 
while T<12; 
    pause(0.2); 
    Dy=1-0.5*exp(-T/4)*cos(pi*T); 
    Y=-(y-2)*Dy+7; 
    Yf=Y(end)+t1; 
    td=[td,T];yd=[yd,Y(end)]; 
    set(D,'ydata',Y); 
    set(F1,'ydata',Yf,'facecolor',rand(1,3)); 
    set(H1,'xdata',[T,13],'ydata',[Y(end),Y(end)]); 
    set(Q,'xdata',td,'ydata',yd) 
    T=T+0.1; 
end 
Kd=find(diff(sign(diff(yd)))==-2)+1; 
X=td(Kd);Y=yd(Kd); 
X=[0,X,td(end)]; 
Y=[yd(1),Y,yd(end)]; 
plot(X,Y,':'); 
Kx=find(diff(sign(diff(yd)))==2)+1; 
X=td(Kx);Y=yd(Kx); 
X=[0,X,td(end)]; 
Y=[-(yd(1)-4),Y,-(yd(end)-4)]; 
plot(X,Y,':');