function dy = lorenz(t,y)

a=10;
b=8/3;
c=28;
dy = [-a*(y(1)-y(2)); c*y(1)-y(2)-y(1)*y(3); y(1)*y(2)-b*y(3)];

% trajetorias:
%y0=[-1 0 0]; [t,y]=ode15s('lorenz',[0 30],y0); plot3(y(:,1),y(:,2),y(:,3));
