distinguish between stable and unstable solutions

hilmeijer — Tue, 21 Apr 2026 07:55:53 -0000

This is not necessarily a well-posed question; you can use MatCont for "standard" dynamical systems analysis, so why would the methods differ from any other tool? So it is the Real Part of Eigenvalues for equilibria, or the modulus of Floquet Multipliers for limit cycles.
You can inspect the stability looking at a Numeric Window, The Data Browser, or change plot properties (EQ/LC if unstable 'Color','red').

distinguish between stable and unstable solutions

CHI — Tue, 21 Apr 2026 03:04:40 -0000

What method should be used in MATCONT to distinguish between stable and unstable solutions?

Prog show no convergence at X0

hilmeijer — Thu, 16 Apr 2026 16:27:15 -0000

Sorry, but we cannot check just any equations. But suppose these are correct.
What you also need is a good initial point. If you start too far away from an equilibrium it will not be able to find it, that is the newton iterations will not converge.
So you may first do a simulation (like in the first tutorial) to observe the behaviour and get an idea of what the system is doing.

Prog show no convergence at X0

Ram singh — Thu, 16 Apr 2026 09:34:23 -0000

Please see where is mistak. it show no convergence at X0.

How to input state-space system in MatCont Systems GUI?

hilmeijer — Tue, 14 Apr 2026 14:27:03 -0000

Thank you for your response.

How to input state-space system in MatCont Systems GUI?

hilmeijer — Sun, 12 Apr 2026 14:52:57 -0000

While I understand how you want to enter your system, the GUI does not work this way. The problem is that we chose to work with scalar state variables. Not with vector-valued ones. In our recent work to work with delays we sort of have an option for vector-valued variables but it is far from automated. Work in progress, if anyone has time.
For now, what you can do, is to create a simple system with the correct number of state variables and parameters but no irrelevant ODEs. After creating the file, you can edit the file and enter the matrix notation for defining your ODEs there directly. Not nice, it is hack, but it will work, and you will need to be careful to work with it.

Unable to switch branch from GPD

hilmeijer — Sun, 12 Apr 2026 11:12:32 -0000

In versions 7p5 and 7p6, we have disabled this menu item for this switch as it is not there, indeed. In the version for maps (MatContM) we have implemented the switch GPD to LPC of double period, but we never created the file for the continuous-time case.
If you want to proceed, you better start a bit away from the GPD point and switch to the doubled cycle from a regular point on the PD curve to detect the LPC point from regular one-parameter continuation. You may have to try starting from both sides of the GPD point.
Good luck

Unable to switch branch from GPD

cheng — Sun, 12 Apr 2026 10:28:22 -0000

Hi,

I am working on MatCont7p4, GUI version.

I have obtained the PD locus and detected several GPD on it.
Now I want to switch the branch from GPD to obtain the LPC locus of double period.
However, when I trying to do that, error appeared noting: Undefined function 'init_GPD_LPC' for input arguments of type 'FacadeMatrix'.

I am wondering what is the possible reason for that?
I have also check the MatCont ManualAug2019, in section 8.4.3, there is no mention on the initializer from GPD to LPC. Is that mean the branch shifting from GPD to LPC locus currently not support?

Thanks a lot for help!
CHENG

Program not run

hilmeijer — Fri, 10 Apr 2026 14:03:32 -0000

No clue, I do not manage to reproduce this error, so cannot help.

Program not run

Ram singh — Fri, 10 Apr 2026 12:30:31 -0000

I manuallly typed model in Matcont>System, itis uplaoded and show in system window but when i run the model it show following lines

Error using feval
Undefined function 'file_Callback' for input arguments of type 'matlab.ui.control.UIControl'.

Error in <a href="matlab:matlab.lang.internal.introspective.errorDocCallback('systems_standalone', 'C:Error while evaluating TimerFcn for timer 'timer-5'

Invalid or deleted object.
Error while evaluating TimerFcn for timer 'timer-6'

Invalid or deleted object.
Altering a system might make older computed data uninterpretable.

screenshots are attached

Recent posts to Discussion

distinguish between stable and unstable solutions

distinguish between stable and unstable solutions

Prog show no convergence at X0

Prog show no convergence at X0

How to input state-space system in MatCont Systems GUI?

How to input state-space system in MatCont Systems GUI?

Unable to switch branch from GPD

Unable to switch branch from GPD

Program not run

Program not run