Fig. 10

Values of z on the Poincaré section \(\alpha\ (\mbox{mod } 2\pi)=0\), \(d\alpha/dt>0\). q increases left to right, then top to bottom, in steps of \(1/12\) starting at \(q=1/12\) (top left). For each plot, 11 different initial conditions were used, and each orbit is shown with a different colour. \(\kappa=-0.5,\eta=0.6,N=4\)