itaps-parallel Clarification of iMeshP_getNumPartNborsArr

[Devine, Karen D]

iMeshP_getPartNborsArr returns, for each input part, the number of parts neighboring that part AND the list of neighbor part IDs.
It is not a union; it returns results for each input part individually.

part[0] has num_nbor_parts[0] neighbors; they are returned in nbor_part_ids[0] .. nbor_part_ids[num_nbor_parts[0]-1].

This function does not have to be used with any other function; it contains complete information itself.

Karen

________________________________________
From: itaps-parallel-bounces at lists.mcs.anl.gov [itaps-parallel-bounces at lists.mcs.anl.gov] On Behalf Of Jason Kraftcheck [kraftche at cae.wisc.edu]
Sent: Monday, November 10, 2008 6:06 PM
To: Carl Ollivier-Gooch
Cc: itaps-parallel at mcs.anl.gov
Subject: Re: itaps-parallel Clarification of iMeshP_getNumPartNborsArr

Carl Ollivier-Gooch wrote:
> Jason Kraftcheck wrote:
>> Does iMeshP_getNumPartNborsArr return the sum of the result of
>> iMeshP_getNumPartNbors for each part, or the size of the difference of
>> the
>> union of the results of iMeshP_getPartNbors for each part with the input
>> list?  For example, if I have three parts arranged such that each
>> neighbors
>> both other parts and I pass in two of the parts to
>> iMeshP_getNumPartNborsArr, is the result:
>>  1) 1 because there is one part not in the input list that is adjacent to
>>      at least one part in the input list
>>  2) 4 because each part in the input list has two adjacent parts
>
> I thought it was
>
>    3) an array that lists the number of part neighbors for each part (so
> (2,2) in this case).  But my understanding may be incompatible with the
> call list.
>

That looks to be correct: it returns an array of results.  Apologies for
any confusion.  I was mixing up this function with
iMeshP_getPartNborsArr (and assuming that given the similarity of names,
that the 'Num' function would be returning the size of the results from
other.)  However, as iMeshP_getPartNborsArr does not return an offset
list, the behavior of that one is still unclear.  Are these functions to
be used together, or does getPartNborsArr return the union of the
results for each part (or the intersection)?

- jason