Duffing.zip_DUFFING_Duffing 信号_duffing matlab_duffing方程_matlab d

% Author: Housam Binous % Forced Duffing Oscillator % National Institute of Applied Sciences and Technology, Tunis, TUNISIA % Email: binoushousam@yahoo.com close all clear clc global gamma omega epsilon GAM OMEG gamma=0.1; omega=1; epsilon=0.25; OMEG=2; % we get chaos and a strange attractor if the driving force GAM=1.5 % Poincar� section is a complicated curve namely a fractal GAM=1.5; [t x]=ode45(@duffing,0:2*pi/OMEG/100:4000,[0 1]); figure(1) plot(t(2000:6000),x(2000:6000,1),'r') axis tight title('time series') figure(2) plot(x(2000:10000,2),x(2000:10000,1),'b') axis tight title('phase space') figure(3) for i=5000:100:127300 n=(i-4900)/100; x1(n)=x(i,2); x2(n)=x(i,1); end plot(x1(:),x2(:),'g.') axis tight title('Poincar� section') % We get a limit cycle when the driving force GAM=0.5 % Poincar� section is a sinle point GAM=0.5; [t x]=ode45(@duffing,0:2*pi/OMEG/100:4000,[0 1]); figure(4) plot(t(2000:6000),x(2000:6000,1),'r') axis tight title('time series') figure(5) plot(x(5000:10000,2),x(5000:10000,1),'b') axis tight title('phase space') figure(6) for i=5000:100:127300 n=(i-4900)/100; x1(n)=x(i,2); x2(n)=x(i,1); end plot(x1(:),x2(:),'g.') axis([-2 2 -2 2]) title('Poincar� section')