I am using Matcont7p1 on Matlab 2019a. I am trying to solve the equilibrium for following coupled ODEs:
dS/dt = Gamma*(N-N0)*S-S/tau_p+Gamma*beta*N/tau_c
dN/dt = P - N/tau_c - (N-N0)*S
First, using orbit, i found the steady state value, then chose the last value as the initial point for equilibrium curve. However, it shows no convergence at x0. I already tried to increase the tolerant to very high, but it still shows the error. May I know what might be the problem? Thank you!
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The problem is that the order of magnitude of your constants is prohibitive. This results in numerical inaccuracies. You may try to rescale your variables such that each term in your equation is more comparable in magnitude.
Best regards, Hil Meijer
From: Sizhu Jiang sizhujiang@users.sourceforge.net
Sent: Sunday, August 25, 2019 9:25 AM
To: [matcont:discussion]
Subject: [matcont:discussion] No convergence at x0
Let me make it clearer,
Here, S and N are coordinates, and others are all parameters.
The value is Gamma = 0.8, N0 = 2e24, tau_p = 1e-11, beta=0.25, tau_c=2e-9, P=5e33.
I can find steady state value when time interval is 50ns.
However, when I tried to plot in equilibrium, I face the error of "no convergence at x0".
Hi,
Let me make it clearer,
Here, S and N are coordinates, and others are all parameters.
The value is Gamma = 0.8, N0 = 2e24, tau_p = 1e-11, beta=0.25, tau_c=2e-9, P=5e33.
I can find steady state value when time interval is 50ns.
However, when I tried to plot in equilibrium, I face the error of "no convergence at x0".
The problem is that the order of magnitude of your constants is prohibitive. This results in numerical inaccuracies. You may try to rescale your variables such that each term in your equation is more comparable in magnitude.
Best regards, Hil Meijer
From: Sizhu Jiang sizhujiang@users.sourceforge.net
Sent: Sunday, August 25, 2019 9:25 AM
To: [matcont:discussion]
Subject: [matcont:discussion] No convergence at x0
Let me make it clearer,
Here, S and N are coordinates, and others are all parameters.
The value is Gamma = 0.8, N0 = 2e24, tau_p = 1e-11, beta=0.25, tau_c=2e-9, P=5e33.
I can find steady state value when time interval is 50ns.
However, when I tried to plot in equilibrium, I face the error of "no convergence at x0".
No convergence at x0
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