M文件:
function xdot=duffing2(t,x,omega)
global omega;
xdot=[x(2);x(1)-x(1)^3-0.3*x(2)+0.25*cos(omega*t)];
计算程序:
clear;
global omega;
omega=1:0.01:2;
for h=1:length(omega)
T=2*pi/omega(h);
[t,x]=ode45('duffing2',[0:T/100:120*T],[0 0], omega(h));
plot(omega(h),x(10000:100:end,2),'k.');hold on
end
M文件:
function xdot=duffing2(t,x,omega)
xdot=[x(2);x(1)-x(1)^3-0.3*x(2)+0.25*cos(omega*t)];
计算程序:
clear;
omega=1:0.01:2;
for h=1:length(omega)
T=2*pi/omega(h);
[t,x]=ode45('duffing2',[0:T/100:120*T],[0 0], omega(h));
plot(omega(h),x(1000:100:end,2),'k.');hold on
end
clear;
omega=1:0.01:2;
for h=1:length(omega)
T=2*pi/omega(h);
[t,x]=ode45('duffing2',[0:T/100:120*T],[0 0],[], omega(h));%加个'[]',就可以运行了.
plot(omega(h),x(1000:100:end,2),'k.');hold on
end