Problem with NonNegative option of ODE45
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Hi everyone!
I'm tryng to solve an implicit system of ordinary differential equation of the type:
where are some parameters. The problem is that if the resulting y is the ode solution ends up to be complex. In order to avoid this I''ve tried to add the option NonNegative to the ode solver. I've a sistem of 5 differential equation so i've written:
options = odeset('NonNegative',[1:5]);
But it does not work because I still find complex solution. Wat's wrong?
Thanks in advance!
3 commentaires
Torsten
le 15 Sep 2022
Modifié(e) : Torsten
le 15 Sep 2022
Maybe your differential equations are such that the solution variables become negative.
E.g. The differential equation dy/dt = -1 with y(0) = 1 has solution y(t) = -t+1 and it will become negative if t>1. The NonNegative option won't prevent this from happening.
The NonNegative option only might help if the variables become negative because of inaccuracies of integration.
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