ZeraouliaSprott¶
A minimal 2-D rational map whose x-recurrence is a single non-vanishing fraction — one of the simplest rational maps reaching chaos via a quasi-periodic route.
Definition¶
\[
\begin{aligned}
y_{0}' &= - \frac{a y_{0}}{y_{1}^{2} + 1} \\
y_{1}' &= b y_{1} + y_{0}
\end{aligned}
\]
Parameters¶
| Symbol | Default | Role |
|---|---|---|
a |
2.7 |
gain of the rational x-recurrence (primary control parameter) |
b |
0.35 |
linear feedback coefficient of y |
Properties¶
Lyapunov spectrum
$+0.00048,\; -0.602$
computed at build
computed at build
Kaplan–Yorke dimension
$D_{KY} = 1.001$
Divergence ∇·f
n/a — discrete map — flow divergence undefined (per-step contraction is |det J|)
Equilibria
1 fixed points
0 stable · 1 unstable
0 stable · 1 unstable
Define it in TSDynamics¶
import tsdynamics as ts
sys = ts.systems.ZeraouliaSprott()
traj = sys.iterate(steps=10_000)
exps = sys.lyapunov_spectrum()
ts.kaplan_yorke_dimension(exps)
Reference¶
Zeraoulia & Sprott (2011), Int. J. Bifurcation Chaos 21, 155-160
