Figure 6

Phase computation scheme depending on linear isochron approximations. An isochron whose linear approximation passes through the point x_ssa(t₀) is found. The point where this hyperplane crosses the limit cycle is ${\mathbf{x}}_{\mathsf{\text{s}}}({\widehat{t}}_{\mathsf{\text{lin}}})$, with ${\widehat{t}}_{\mathsf{\text{lin}}}$ the solution of this phase computation scheme. The difference between the exact solution $\widehat{t}$ and the approximate solution ${\widehat{t}}_{\mathsf{\text{lin}}}$ is reduced if the isochrons are close to being linear.