The Rossler Attractor

(24 Votes)
1.0 (Updated 16 years ago)
February 02, 2007
Reaktor 5 or lower


This instrument reconstructs Rossler attractor time series as audio signals using core cells.


Ignasi Alvarez Garriga
9 years ago
Hi Jakob, sorry for being so late in answering... 1 - the integration scheme used is y'= 1/2 * [ f(dt) + f(dt/2) ] ... I think it is a Heun method 2 - as 0.1 is a constant, in reaktor it is supposed to trigger only at onset time, so this is not really added, but just an initialization 3 - I suppose you refer to the latch feeded by 0... this is not really added. This is simply triggered when clock signal is directed to the latch : a dirty trick to have an on-off switch ... hope it helps.
Jakob Metzger
10 years ago
This is really great if you want to learn how to implement your own mathematical ideas. Some things are unclear to me though (but this might be my patchy knowledge of core): 1. I dont understand the integration scheme that is used: If I read it correctly, you integrate y'=f(y) by using y+ f(y+f(y)*dt)*dt/2, which I dont recognize as Euler, midpoint, or any other Runge-Kutta scheme. Can you explain? 2. why do you add a constant 0.1 to the initial y-1? 3. after you apply Rossler eqs for the second time, 0 is added to the result before multiplying it with dt/2. Why? Again, really inspiring stuff!
Ignasi Alvarez Garriga
16 years ago
Thank you Nathan for your kind comments. I appreciate very much that you found it beatifully laid out, cause, you are right: this is a mathematical practice... but I do not resign to find a real musical application for this. Thanks for the nice comparison to the Rosetta stone, but if anyone wanting to explore it for musical purpouses needs any more clues, I check often n.i. user forum, so please post there (and if someone can help me to understand core a bit more, please attend this : ) By the way, I am sorry I do not know who Tom Yorke is ...
Nathan Ramella
16 years ago
The Rossler system is the work of Otto Rossler a German biochemist. It is a model of chemical reaction and is considered one of the more notable strange attractors and often cited as an example of deterministic chaos. The system is represented by 3 coupled non-linear differential equations. dx / dt = - y - z dy / dt = x + a y dz / dt = b + z ( x - c ) where a = 0.2, b = 0.2, c = 5.7 That being said, this ensemble lives up to the name. I would guess that this is more of a mathematical practice for the author than an attempt to make an enduring musical tool. The ROSSLER component written in core is beautifully laid out, looking more like a circuit than the average Reaktor component. Core programmers will likely find inspiration in it as a mathematical Rosetta stone. As far as the sound, its about what you would expect with the phrases ’strange attractor’ and ‘deterministic chaos’ in its history. I was able to make some interesting WWII propeller plane noises with it, the presets mostly make clicking and popping noises. I think it’d be more useful as the source of CC data for other instruments or effects than its own audio data. But who’s to say Thom Yorke won’t come along and use it on his next album and be heralded as a genius. Summary Straight from the chalkboard and into your ears. It’s math you can hear. Sounds like: Math, no bleeps or bloops, lots of pops and grumbly noises . Verdict: Are you going to let Thom Yorke get all the acclaim? Well, are you? Also: Mathematical Rosetta stone for core programmers