[MOAB-dev] Edges at the ends of a periodic mesh?

[Xiabing Xu]

On May 23, 2012, at 9:13 PM, Robert Jacob wrote:

> 
> 
> On 5/23/12 9:01 PM, Timothy J. Tautges wrote:
>> Be careful about the parallel case though, where on each proc sharing the edge the edge is represented.
> 
> So in the parallel case the edge WOULD be represented on both sides if there are multiple processors in the j direction?
> 
Do we have to declare the global number of vertices (gDims) as the number of quads or the number of quads plus one?

Xiabing

> Rob
> 
>> 
>> Also, if you're just trying to create all the edges in one big batch, just put all the quads in a range, then call get_adjacencies, with the last argument Interface::UNION, and that should create/return all of them.
>> 
>> - tim
>> 
>> ----- Original Message -----
>> From: "Iulian Grindeanu"<iulian at mcs.anl.gov>
>> To: "Robert Jacob"<jacob at mcs.anl.gov>
>> Cc: moab-dev at mcs.anl.gov
>> Sent: Wednesday, May 23, 2012 12:34:12 PM
>> Subject: Re: [MOAB-dev] Edges at the ends of a periodic mesh?
>> 
>> 
>> 
>> 
>> ----- Original Message -----
>> 
>> 
>> 
>> Hi,
>> 
>> If I have a 2D rectangular mesh which is periodic in one direction, lets
>> say the j direction, then the leftmost and rightmost edge of the mesh
>> are really the same edge. Do they both need to be declared in MOAB? Or
>> does the periodic property mean you only need to describe one of the
>> edges and the other end will know its adjacent to it?
>> 
>> Thanks,
>> Rob
>> Hi,
>> I assume that you use ScdInterface;
>> If the box is periodic in j direction, the nodes in that direction will be "periodic".
>> Nodes are not duplicated, the edges that you get on the leftmost and rightmost sides are really pointing to the same nodes, they will not be duplicated, either.
>> 
>> How do you get edges after you create quads?
>> You can use "get_adjacency" methods, with "create_if_missing" flag true. Only one edge would be created.
>> The problem is that the order in which these are created is not very "structured"
>> Or do you create them with new scd boxes, of dimension 1, in a loop over i (and then j?)? In that case, you have complete control over "order" they are created in.
>> I hope this helps.
>> Iulian
>> 
>> 
>> Iulian
>>