Time-points close to event occurences in test #0041 about sbml-test-suite HOT 4 CLOSED

It's important to realize that the provided 'absolute' and 'relative' values are not tolerances, but levels at which your results will be judged. It is a common practice to set the tolerances for your particular simulator at 10x or even 100x smaller than the 'absolute' or 'relative' values.

However, I'm not sure even with this caveat why you're having a problem with this model. If you're within 100x smaller of the tolerances of the given values, that means that at (say) time point 2.3, the value of S1 should be 0.100259. Shortly thereafter, the event will fire. If your event is firing before time point 2.3, that's a clear problem with your simulator, since 0.1002 is still 20x the relative tolerance (0.0001) greater than 0.1. If it's firing after time point 2.4, that's a similarly odd problem, as it should have reached a value well below 0.1 by that time (it would be 0.09 or so).

I'm more than willing to adjust the test if the tolerances are really out of wack, but my own suspicion is that this is indicating a problem either in the tolerance settings, or in the simulator itself. This test has been in the SBML Test Suite since its inception, and to my knowledge, no other simulator has had any issues with it.

If time points 24 and 47 are the only time points that vary from the expected results, this is also confusing to me, as I would expect errors at those time points to propogate to future time points: both S1 and S2 change smoothly in time when not being changed by events. Having the event fire at a time sufficiently off from expected would under normal circumstances cause all affected variables to display a corresponding shift in value from expected.

Original comment by: luciansmith

from sbml-test-suite.

Okay that explains my problems. I passed the two values as absolute and relative tolerances to the solver. If I use more restrictive tolerances the problems disappears.

Original comment by: ffroehlich

from sbml-test-suite.

• status: open --> closed
• assigned_to: Lucian Smith

Original comment by: luciansmith

from sbml-test-suite.

Excellent! Glad to hear it. I've added a task to make this more clear in the documentation.

Original comment by: luciansmith

from sbml-test-suite.