% Animates the solution of the Lorenz equations


% initial conditions
y0 = [8 9 9.5];
ystart = y0;

% timestepping data: 
tstep = 0.4;
nstep = 200;

% labelling axes
axis([-20 20 0 40])
     xlabel('x','FontSize',20)
     ylabel('z','FontSize',20)


% creation and acquisition of frames
for i = 1:nstep

tspan = 0:tstep/100:tstep;
[t,y] = ode45(@lorenz,tspan,ystart);
line(y(:,1),y(:,3))
hold on
ystart = y(101,:)
h = gcf;
M(i) = getframe(h,[5 5 480 380]);

end

movie(M);
movie2avi(M,'butterflyr21','fps',4);