Activity for Sergey Novak
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Sergey Novak posted a comment on discussion Help
Thank you for your help
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Hello! I got an issue with Matcont. I tried to continue limit cycle from GH and got a message in matlab console "Current step size too small". I tried to change ntst, adapt, stepsize for control parameters, tolerance, amplitude with no result. I also tried to use period as one of the control parameters and to continue the limit cycle from GH by period and another one of control parameter of the system. Unfortunately, I got the same message "Current step size too small" when tried to detect an LPC...
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I was able to continue the bifurcation curve of the saddle node of the limit cycles with "amplitude" 1e-1 Thank you so much for your help
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Hello, I am trying to continue the saddle-node bifurcation curve of limit cycles from the generalized Hopf bifurcation. When starting the curve calculation, matcont freezes for several minutes and does not respond in any way. Then completes the curve calculation. When I check the calculated curve, I see only 1-10 points there. I've tried changing the fun tolerance, the test tolerance, and the var tolerance. Increasing the tolerance to 1e-04 caused the matcont hang to disappear, and the calculation...
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Thank you for help
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Hello, I see that there are no complex conjugate numbers with a purely imaginary part on the Hopf curve. I don't quite understand if this is really a Hopf curve or something else. Thank you for help
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Hello, I see that there are no complex conjugate numbers with a purely imaginary part on the Hopf curve. I don't quite understand if this is really a Hopf curve or something else. Thank you for help
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Thank you for help
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Hello I want to use the first Lyapunov coefficient to determine which branch of the Andronov-Hopf bifurcation corresponds to the supercritical and which to the subcritical I assume that h(5, :): HH is the first Lyapunov coefficient, but it's not entirely clear why it has such a name, shouldn't it be h(5,:): GH? My system is three-dimensional and HH bifurcation is not possible, but I see its name in the output table I guess it's actually GH, but I doubt it Thank you for help
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Thank you so much for your help There is a message about this in the console I didn't pay attention to her before
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Hello, i find zero hopf bifurcation and I decided to check the eigenvalues of the equilibrium This codimension two bifurcation is characterized by the conditions λ1=0 and Re λ2,3=0, but I don't see the imaginary part being zero I don't quite understand how matcont discovered this bifurcation Thank you for help
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Thank you so much for your help
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Hello, you need to go to file f and scroll to the bottom. The last lines should correspond to your own eigenvectors.
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Hello, I have a bifurcation homoclinic curve derived from the Bogdanov Takens bifurcation. Tell me please how can I view a homoclinic solution for any point with a curve? I manage to look at the homoclinic solution only for some points. As an example, I attached a video. Thank you for help Best regards, Sergey Olenin
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With the help of another programming language, I conducted an analysis and managed to understand a little what happened to the homoclinic orbit. I have attached a photo of the bifurcation. Unfortunately, I do not know what it is called. Can i somehow configure the matcont so that it captures such a situation? Thank you in advance for your help
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Hello! I built a homoclinic curve and decided to check the homoclinic orbit. When I checked, I found that it doesn't look like a homoclinic at all. I tried to fix it in various ways. I increased CheckClosed and ntst and it didn't help. I tried to repeat the whole procedure, that is, searching for a homoclinic orbit using HomotopySaddle, setting the parameters differently and it also didn't help. I seem to be doing everything according to the instructions, but I don't understand why this result is...
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Hello! Previously, it was possible to find a homoclinic orbit. I took these parameters. I am trying to calculate a homoclinic loop, and for this I am separately looking for an equilibrium state, eigenvectors, and deviate from the equilibrium state along a stable manifold as follows: fixed_point + epsilon * vector_stable, where epsilon = 1e-7 I can't get the homoclinic loop to saddle focus and I don't quite understand why and how it can be fixed
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Thank you for tip Matcont can not use limit cycle continuation? How does matcont determine the distance to a stable manifold and can i calculate stable manifold wth matcont and then plot it and attractor in 3d phase space?
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That is, it is not a homoclinic even if it looks like it and there is no point in changing the code? I compared the phase portraits between what matcont called the homoclinic and this. There are no visual differences and the distance from the saddle focus to the trajectory from the attractor is the same In my case, the trajectory passes only next to a stable manifold, but does not fall into it? If so, why does it look like homoclinic attractor
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Can I change the code so that SParam1 and SParam2, instead of zero, could be, for example, 0.01? I don't understand a bit why matcont can't find a homoclinic with other parameters, when visually it's clearly her. I calculated the distance from the saddle focus to the trajectory from the attractor and it was machine zero (pink and black curve it is trajectory with different initial condition) (Unfortunately, I couldn't upload the video, because I exceeded the allowed size)
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I sent a message Thank you so much!
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Thank you! In what format can I send you the model? In the form of matcont files?
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I tried these parameters and got the same error. Also I tried with ntst = 100, MaxStepsize = 0.0001 Have i to change these parameters until there is convergence to the equilibrium state?
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Thank you, now this part is working I need change settings Continuer for fix this error or i need less time interval before this stage?
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I shortened the interval I don't fully understand which parameter should I use? Earlier you wrote that UParam1 and SParam1. I tried using them and it didn't help
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I recorded video with my steps before error I choose different parameter and it is not help I mistake before continuation ?
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Yes, it is mentioned. I reproduced examples from tutorials The problem is simply that, repeating the same actions as in the tutorials for my model, I get an error
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I get the following result Do I need to get parameters close to zero at the simulation stage?
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Do I understand correctly that at this stage I should, for example, take UParam1 = -1, UParam2 = -1?
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I have next error How can i fix it? I need take more time for integrate my system? Also I don't really understand which parameter I need to use UParam1 or UParam2 if the unstable invariant manifold is two dimensional
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I have next error How can i fix it? I need take more time for integrate my system?
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I want to show the existence of Shilnikov attractor For example i calculated bifurcation curve of double period of limit cycle
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I want to show the existence of Shilnikov attractor
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I have Shilnikov attractor and i want get bifurcation curve when Shilnikov is exist. That is i have saddle focus(1,2), negative saddle value, small distance between trajectory from attractor and saddle focus, more accurately machine zero.
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Hello Is it possible to calculate the bifurcation curve for the saddle focus? If it is not possible, are there packages that can do this, or does it only remain to write the code for this?
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Thank you! It is worked
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I recorded video with my steps In what i mistake?
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Hello! I try repeat first example from DOI: 10.1145/2168773.2168776 And i get next error. How can i fix this? Also i try repeat example from https://dercole.faculty.polimi.it/tds/matcont/6/homcont.pdf and get the same error
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