Christophe LETELLIER
04/06/2009

This system is made of three ordinary differential equations

The parameters are chosen such as [1]. This system has as a solution a fairly complicated attractor, shown in (Fig. 2).

**Fig. 2 : Chaotic attractor solution to the 84 Lorenz system.**

A data set can be downloaded. There are three columns for *x*, *y* and *z*, respectively.
In addition to its quite complex dynamics, this system is characterized by the low observability coefficients
,
,
,
that is, the dynamical variables can be ranked as

[1] E. N. Lorenz, Irregularity : a fundamental property of the
atmosphere, *Tellus A*, **36**, 98-110, 1984.