Not a publication. The only one being an asshole here is you Please Register or Log in to view the hidden image!
Pete, I've looked at your code and to be honest, I am not sure we are considering the same thing. It appears you are using discrete steps and not a continuous model, but it is hard to tell because there isn't really a time involved. For discrete models, the magnitude of the pole must be less than 1 for the system to be stable which I think is what you are doing and in that way, it in fact would be possible to create a positive feedback with a pole less than 1 by ensuring that Gain x Feedback is less than 1. However, if you tried to put this into a more complex system, it is not guaranteed that the magnitude of the pole will still be less than 1.
Definition of Plagiarism: n 1: a piece of writing that has been copied from someone else and is presented as being your own work 2: the act of plagiarizing; taking someone's words or ideas as if they were your own It doesn't say anything about having to publish the writing in a professional journal or other publication. You took someone's ideas/words and posted them here without reference. That is plagiarism.
I presented it as everything we needed to know about positive feedback - not everything I know about positive feedback. I in fact had already said that I did not know anything about positive feedback. Read it again, " And here is everything you need to know about positive feedback: Feedback is ..." I did in fact just forget to present the source because it was almost 3AM! Have fun trying to claim that I actually tried to claim that as knowledge of my own when I had already stated to the contrary, that I in fact did not have any experience in using positive feedback. I see that neither you nor funkstar have anything substantial to contribute to the conversation here. How about you stick to the conversation we were having on the solar system as I suspect you have no knowledge of feedback systems. Or if you do have knowledge, why don't you contribute your knowledge as related to the stability/instability of positive feedback systems. I still think any positive feedback can lead to instability even if it was initially stable (via making the system more complex with other feedbacks for instance).
Then perhaps you should try to understand what I'm talking about, instead of forcing it into the context of control systems, hmm?? Naturally, it was much easier to code the model as a discrete system. But surely I've given you enough info to work it out as a continuous system? It's not difficult, surely - a signal goes into mike, doubles before exiting the speaker, and 20% of the output feeds back in with an arbitrary delay. I'm sure you can do it, unless you're a slave to the theory without any real understanding...
You cannot model a continuous system with a discrete example. A discrete system is synonymous with just taking samples and does not model reality. A mechanical system can be made discrete by forcing delayed samples, but otherwise, you would be dealing with continuous model systems. You aren't sure you can do what?
Then show me! Put your money where your mouth is! Show me a continuous model of the system and how its behaviour differs from the discrete model... otherwise, you're just spouting hot air with zero credibility.
Yes, you can. It's the only way when a general solution is impossible (as with most real-world phenomena). Accuracy and resolution are gained by reducing the iteration step size. How do you think supercomputer modelling works?
SL, no you cannot. The mathematics are totally different. For instance, for a continuous model to be stable, the poles must be less than 0 or equal to 0 for neutral stability. For a discrete system, the magnitude of the poles must be less than 1. This means that a pole of -5 is stable in a continuous model and unstable in a discrete model. Similarly a pole of .5 is stable in a discrete model and unstable in a continuous model.
Oh, so you're saying that all the discreet simulation models of CONTINUOUS systems in astronomy and physics are impossible?
You have to analyze the time response which involves doing a Laplace transform. The time response will show if the system is stable or unstable.
No. You have to transform the continuous model into a discrete model. Like I said, the mathematics are completely different for the two situations and they are not interchangable. I did however use the term "model" wrongly, I meant it in the context of modeling the mathematics. Let me restate what I meant. You cannot use the mathematics for a discrete system to analyze a continuous system without first converting the continuous system to a discrete system (by taking samples of the continuous cycle for instance).
As long as the transform from one to the other is correct, the behavior should be the same, with accuracy based on iteration (sample) step size.
Yes, but the mathematics to determine the behavior is different for each which is why you get different poles for instance.
No argument. I haven't done a pole/zero analysis in a long time... Bode plots for amplitude and phase for sure...
It's more involved then just giving a simple formula, while you can use the integral formula, it is more common to just use presolved examples available in a table at this site. Remember that all zeros and all poles are the 's' variable. Edit: actually the relationship between the space variable s and the poles/zeros is a little bit more complicated, I can clarify how to change between the two if you like. Also, solving partial fractions is often involved in separating a transfer function into terms that appear in the listed table.
