ODE15S problem with solver

I try to solve a stiff non-linear ODE including a time-dependent term with ode15s (and I tried others too) using mass matrix. Matlab starts computing but then displays a warning and aborts:

Warning: Failure at t=4.691305e-05.  Unable to meet integration tolerances
without reducing the step size below the smallest value allowed
(1.084202e-19) at time t.

Does anybody have an idea how to avoid this?

Thanks!

Answer 1

[Lucas García]

Have you tried with all the different stiff solvers available? ode15s, ode23s, ode23t and ode23tb. It could be that the problem you are trying to solve is too stiff for a solver but can be solved with another.

Also, it can be a singularity issue. Maybe this technical solution can help:

http://www.mathworks.com/support/solutions/en/data/1-192Z0

[Christian Lenz]

Thank you, Lucas. Yes, I tried them. But none seems to work out-of-the-box... I tried to tune parameters. It seems that the time-dependent term is very critical as soon as it changes fast, the solver aborts with the above warning.