MATLAB Answers


Stiff differential equation solvers

Asked by Deepa Maheshvare on 9 Jan 2019
Latest activity Commented on by Deepa Maheshvare on 11 Jan 2019
I'm trying to understand how the stiff differential equations are solved in ode5s and ode15i.
If my understanding is right, stiff equation solver implements BDF method if specified in the option given in the call to the solver.
What happens in implicit solver?
e.g. if dx/dt = f(x,t)
is written as
x(n+1) = x(n) + f(x(n),tn) + f(x(n+1),t(n+1))
Is it solved using non-linear equation solver?
Could someone explain? Is there any example files that are available for implementation of BDF and implicit solver?


Thank you.I had an understanding that ode15s wasn't implicit. Now, it is clear to me that it is an implicit solver.
I'm sorry if any of the notations that I used wasn't clear. My equations are ode's which come from convection-reaction-diffusion system. The functions on the RHS contain variables that are functions of time, but not time derivatives.
Forget my comment.
I mixed your problem up with another one.

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1 Answer

Answer by Steven Lord
on 10 Jan 2019

There are several stiff solvers. See the "Basic Solver Selection" section on this documentation page for a table indicating which solvers are stiff and which are nonstiff. For more details about a particular solver, see the Algorithms and References sections on each solver's documentation page.


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