Unable to meet integration tolerances without reducing the step size below the smallest value allowed (3.552714e-15) at time t.

Hello

Using the parabolic-solver to solve thermal conduction equation I got following message: Warning: Failure at t=1.127658e+00. Unable to meet integration tolerances without reducing the step size below the smallest value allowed (3.552714e-15) at time t. The failure occurs in ode15s-solver.

I have absolutely no idea where to start failure search... and I am very grateful for any help.

LF

Answer 1

[Star Strider]

That error usually occurs when your function creates a singularity or other discontinuity (with an Inf or NaN result) at the specified time. The only way to determine that is to examine the output of your ode15s call to see what the values are when it stops.

Plotting the output (all columns of the result as functions of your independent variable) will probably tell you everything you need to know about the problem.

[MarionJ]

Actually I've increased the size of the swapfile of my RAM and the error seems to be gone. Coincidence?

[Rameen Mirzada]

i have the same issue anyone could answer this question would be a great help

[Amanda Gregory]

Also experiencing this issue. My understanding was the PDE solver serched for NaN values to determine nonlinearity, is this not the case?

[Torsten]

is this not the case?

No. Detecting NaN values during a computation will make the solver stop immediately. This applies at least for the underlying ODE integrator (ode15s). I don't know about possible functionalities of the superordinate PDE solver.