function AA

global mu w F;
mu=0.3;w=1.2;
cF=[0.20 0.27 0.289 0.293 0.32 0.35 0.37 0.4 0.65 0.7];
k=0;
for F=cF
    k=k+1;
[t,x]=ode45(@duffing,[0,2000],[2,0.01]);
x1=x(:,1);
count=find(t>1800);
Y=x1(count,:);
t1=t(count,:);
subplot(5,2,k)
plot(t1,Y)
xlabel('t');
ylabel('x ');
s=['t=0 x=2 y=0.01 F=',num2str(F)];
title(s);
end

function dx=duffing(t,x)
global mu w F;
dx=[x(2);F*cos(w*t)-mu*x(2)+x(1)-x(1).^3];

function aa
global mu w F;
mu=0.05;w=1;
F=7.5;
x0=[1;0.2];
tspan = 0:0.1*2*pi:50000;
[t,y]=ode45(@duffing,tspan,x0);
m=zeros(7000,1);
n=zeros(7000,1);
for i=1:7000
    m(i,1)=y(10*i,1);
    n(i,1)=y(10*i,2);
end
plot(m,n,'k.','markersize',1);

function dx=duffing(t,x)
global mu w F;
dx=[x(2);F*cos(w*t)-mu*x(2)-x(1).^3];