MATLAB: How to add arrows to the phase plane produced

directional-arrowsMATLABode45phase plane

I have the following matlab code that produces the phase plane for the state variables and I want to add arrows in order to show that my system goes from the initial conditions point to the stability point which is (0,0). How is that possible ?
tspan = 0.0:0.1:10;
[t,w] = ode45(@ode, tspan, [-0.5;-0.5]);
plot(w(:,1),w(:,2))
function dx = ode(t,x)
    dx = [x(2) ; - x(2) - 4*x(1)];
end

Best Answer

tspan = 0.0:0.1:10;
[t,w] = ode45(@ode, tspan, [-0.5;-0.5]);
plot(w(:,1),w(:,2))
hold on
quiver(w(:,1),w(:,2),gradient(w(:,1)),gradient(w(:,2)))
end
function dx = ode(t,x)
    dx = [x(2) ; - x(2) - 4*x(1)];
end
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