function dy = Hopf_eqn(t,y)
global lambda w a gamma1 gamma2
dy = zeros(2,1);
dy(1) = lambda*y(1)-w*y(2)+a*y(1)*(y(1)^2+y(2)^2)+gamma1*y(1)^3;
dy(2) = w*y(1)+lambda*y(2)+a*y(2)*(y(1)^2+y(2)^2)+gamma2*y(2)^3;