iRel.h interface update [was iRel proposal: removing non-one-to-one relation functions]

[Tim Tautges]

On 10/28/2010 03:10 PM, Mark Shephard wrote:

>
> Considering that the iRel specification at this point came from one
> place with in essence, no input for others that have implementations, it
> is a reasonable thing to be careful and if we need to modify things so
> relationships are support for all of ITAPS.
>

To be fair, input was solicited many times, starting about year 2.5, and none showed up until about year 7.

- tim

>>
>> ** Between different implementations of ITAPS interfaces
>>
>>> This avails non set-dominant impementation to support "iRel"
>>> effectively without interfering set-dominant
>>> implementation and not against neither of "interchangeability" and
>>> "interoperability".
>>
>> I must confess that my knowledge of other ITAPS implementations is
>> limited, but are you suggesting that a) you wouldn't support the
>> set-based functions in iRel at all, or b) that you'd support them, but
>> they wouldn't be the optimal way of working with data in your
>> implementation?
>
> We support all the set functions. However, controlling everything by
> sets becomes quite computationally intensive when you are doing lots of
> local mesh modification, which is exactly what users of out
> implementations are doing. Thus although we support sets, the
> applications we support typically use sets in specific ways that cause
> no complexity with the sets that are in place.
>
>>
>> If we're talking about (a) here, this is a pretty optimistic view,
>> perhaps overly so. Clearly, if one implementation supports a given
>> function and the other does not (e.g. a "set-dominant" interface doesn't
>> fully support arrays or an "array-dominant" interface doesn't support
>> sets), that function is by definition not interchangeable. For
>> MOAB/CGM/Lasso, this problem is academic, since MOAB and CGM support
>> both set- and array-based operation (and Lasso will too, however it ends
>> up looking), but for other implementations, this could be more serious
>> issue. In practice, this would mean that you'd be unable to use many of
>> the tools we write that target ITAPS interfaces.
>>
>> If we're talking about (b), see my discussion above on relation
>> cardinality.
>>
>> - Jim
>>
>
>

-- 
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              Tim Tautges            Argonne National Laboratory
          (tautges at mcs.anl.gov)      (telecommuting from UW-Madison)
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