function xout = lorenzSyS(x)
% rhs for lorenz strange attractor system
sigma = 10;
b = 8/3;
r = 28;
xout    = x;   % make sure shapes agree 
xout(1) = sigma*(x(2)-x(1));
xout(2) = r*x(1) - x(2) - x(1)*x(3);
xout(3) = x(1)*x(2) - b*x(3);