Figure 3

Three-dimensional models with ${\mathit{\sigma }}_{\mathbf{1}}\mathbf{=}\mathbf{1}$ and ${\mathit{\sigma }}_{\mathbf{2}}\mathbf{,}{\mathit{\sigma }}_{\mathbf{3}}\mathbf{\in }\mathbf{\{}\mathbf{-}\mathbf{1}\mathbf{,}\mathbf{1}\mathbf{\}}$. The four thicker curves denote the trajectories of the solutions of equation (4.1) with $n=3$ and the other curves are the projections of the trajectories in two planes among $x_1{x}_2$, $x_1{x}_3$, and $x_2{x}_3$ planes. The four larger stars denote the limits θ (see Examples 4.7 and 4.8). (a) $({\sigma }_2,{\sigma }_3)=(-1,-1)$ and $\mathit{\theta }=(1,0.25,0.25)$. (b) $({\sigma }_2,{\sigma }_3)=(-1,1)$ and $\mathit{\theta }=(1,2,3)$. (c) $({\sigma }_2,{\sigma }_3)=(1,-1)$ and $\mathit{\theta }=(1,2,3)$. (d) $({\sigma }_2,{\sigma }_3)=(1,1)$ and $\mathit{\theta }=(1,2,3)$.