ODE45 not producing outputs test does not finish

function xdot = TREE(t,x)

xdot = zeros(8,1);

xdot(1) = -1.71*x(1)+0.43*x(2)+8.32*x(3)+0.007;

xdot(2) = 1.71*x(1)+8.75*x(2);

xdot(3) = -10.03*x(3)+0.43*x(4)+0.035*x(5);

xdot(4) = 8.32*x(2)+1.71*x(3)-1.12*x(4);

xdot(5) = -1.745*x(5)+0.43*x(6)+0.43*x(7);

xdot(6) = -280*x(6)*x(8)+0.69*x(4)+1.71*x(5)-0.43*x(6)+0.69*x(7);

xdot(7) = 280*x(6)*x(8)-1.81*x(7);

xdot(8) = -280*x(6)*x(8)+1.81*x(7);

end

tspan = [0 300];

x0 = [1; 0; 0; 0; 0; 0; 0; 0.0057];

options = odeset('RelTol',1e-3,'AbsTol',1e-6);

tic

[t,x] = ode45(@TREE,tspan,x0,options);

timeode45 = toc

Answer 1

[Torsten]

Use a stiff integrator, namely ode15s instead of ode45.