itaps-parallel Proposal for handling queries with parts, sets, and partitions

[Mark Shephard]

Tim,

No that is not true!!! The questions asked by an interface do not 
require specific information be stored. It requires the ability to 
answer the question!!!!! We very much use a partition model without sets 
or explicit storage of reverse classification. Reasons for this are 
explained in various papers. However, knowing that is less the issue. 
The reason for interface API is to allow people to answer the questions, 
not force them to use specific structures.

Mark

Tim Tautges wrote:
> Then why do we need functions operating on parts or partitions at all? 
> Those are reverse classification-type queries, right?
> 
> - tim
> 
> Mark Shephard wrote:
>>
>>
>> Since the first thing that was agreed to is that there would be the 
>> ability to deal parts that does not require an implementation to do 
>> things via sets (reverse classification), I sure hope we are not 
>> getting this issue confused again. As discussed in some technical 
>> detail at the boot camp, there are two high level approaches one based 
>> on classification (no use of sets) and reverse classification (what 
>> sets do well). All the SCOREC tools that are being used for parallel 
>> adaptive simulations, and (in the past) for parallel mesh generation, 
>> are based on a classification approach.
>>
>> Onkar Sahni wrote:
>>>> So again, I go back to asking: what are the core needs that prevent us
>>>> from using sets as both parts and partitions?  The entity set mechanism
>>>> was designed with this specific usage in mind.
>>>
>>> If "sets as both parts and partitions" mean using entity-sets then we 
>>> have
>>> already discussed this in great detail. I think the question in 
>>> discussion
>>> is irrespective of how one implements parts and partitions? If I
>>> understood the question right then we need to answer queries which 
>>> involve
>>> a specific part and a specific entity-set (where entity-set may span 
>>> more
>>> than one part, may be local to a process). Now, if it is implied that
>>> choosing entity-sets for both parts and partitions allows to use set
>>> operations (booleans), outside the interface explicitly by applications,
>>> to answer such queries well then applications might as well do it in 
>>> other
>>> equivalent ways (for example, loop over entities in set and ask 
>>> residence
>>> parts to get entities in the entity-sey belonging to a specific part).
>>>
>>> - Onkar
>>>
>>
>>
>