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From: Jan Simon on 14 Sep 2009 04:19
Dear vinu georgep!

> while using matlab i encountered a problem
> >> [t,y] = ode15s(@hydrovdp,[0 86400],[1000 1]);
> Warning: Failure at t=5.676399e-010. Unable to meet integration
> tolerances without reducing the step size below the smallest value
> allowed (1.654361e-024) at time t.
> > In ode15s at 819

This might be a problem of your HYDRoVDP function. The integrator stops after a few or a single step, because it cannot find a new step size, whichsatisfies the error control. The default error bounds are not too tight usually (RelTol = 1e-3, AbsTol = 1e-6), but this depends on the scaling of your problem! If your data has a magnitude of e.g. 1e16, the absoulte tolerance of 1e-6 let resign the integrator.

Good luck, Jan
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