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* Nicolas Le novère <lenov@ebi.ac.uk> [2010-06-25 22:27] writes:
> On 25/06/10 18:09, Stefan Hoops wrote:
>
> > No we are not saying the same thing. It is not possible to mix
> > undefined and ordered.
>
> I agree with Stefan. The situation is very similar to the unit one. If
> priorities are used, they must be used on all events. If a single event
> misses a priority, then all the other priorities are ignored. The
> priorities do no matter at all. People are free to do whatever they want
> with the events.

I don't think this is quite what Stefan was saying (though maybe it was!)
but I disagree. You put priorities on the events that might clash. You
leave the rest alone. I don't understand why this is even controversial.

> I do not see any advantage at all in mixed situations. And actually, I
> cannot imagine how such a model would be generated since SBML is supposed
> to be written by a software. Either this software generates priorities, for
> all events, or not.

Priorities are added, as I see it, by hand. I cannot envision any
algorithm that generates priorities automatically for all events, unless
it is to give them all the same priority in order to ensure randomness.
But whenever two priorities differ and were not randomly generated, the
reason it was so is due to a specific decision on the part of the modeler.
A decision that need not be made for all events, just the ones whose
EventAssignments might clash in some fashion.

Certainly if I add a syntax for event priority to Antimony, it will be
trivial to generate models with multiple events, some of which will have
priorities.

It doesn't matter (to me) *why* the modeler chose to put priorities on
some events and not others. What matters is that the intent is clear and
that a simulator can follow that intent. If I put some priorities on some
events, it means I care about the order of those events, should they
execute simultaneously. If I do not put priorities on other events, it
means I do not care about the order of those events. If they're mixed, it
means exactly the same thing: some of them, I care about the order, and
some, I don't. I believe that this is trivial to conceive of,
communicate, and execute, and see no reason why we should claim that we
have no idea what's going on and throw up our hands in despair.

-Lucian
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