nonlinear dynamics, chaos, return maps, exponents

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Wed, 09/03/2008 - 11:58 am

Fellow Igorinians,

I have a definite need to assess a recent data set of approximately 3000 data points that appear to display a type of spatial chaotic (or nearly chaotic behavior). I do have some canned software for evaluation purposes (Sprott's Chaos Analyzer) but I was hoping to find some existing code that was a little more robust and had quality plotting capabilities. I admit that, although I have used IGOR for the past 10 years, I have spent little time developing code to implement other than an occasional curve fit. I would like to be able to plot an x(n)-x(n+1) return map, assess the various exponents/dimensions (Lyapunov, fractal, Hausdorff) and ultimately develop a phase-space plot of the attractor if it exists. I know I'm asking for the world here, but can anyone help with any or all?
Any assistance would be greatly appreciated.
Respectfully,
Dr. Mike Boteler
Mike-

For the graph of x(n)-x(n+1), try

Display wave[0,n-2] vs wave[1,n-1]

Naturally, substitute the real name of your wave for "wave", and the number of points in the wave for n. The New Graph dialog can do this if you use the More Complications, er, I mean More Options button and click Add and edit the ranges in the list.

I might also suggest that you post a query on the Igor Mailing list- there are still lots of people who haven't caught on to Igor Exchange.

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

September 9, 2008 at 03:51 pm - Permalink