[MOAB-dev] Sparse vs. dense tags

[Tim Tautges]

It should be sparse.  The crucial difference is that when a dense tag is given a value, all the entities in the same 
sequence as the one whose tag is being set are also allocated storage for that tag.  In the case of many sets, this 
would waste some storage.  It's a bigger problem when tagging entities, though.

- tim

On 12/15/2010 03:09 PM, Steve Jackson wrote:
> The "GEOM_SENSE_2" tag, used to record the volumes on either side of a surface, is not consistently created as either sparse or dense.  When created from DagMC and its utility tools, the tag is created as dense, but when created from GeomTopoTool (via ReadCGM), the tag is sparse.
>
> Questions:
>
> * How big a problem is this inconsistency?  It doesn't seem to cause any errors or disruption.
>
> * Should the tag be dense or sparse?  The tag is only used on entity sets that represent surfaces, so my guess is that it ought to be sparse, but I don't understand the implementation difference deeply enough to be sure.
>
> ~S

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              Tim Tautges            Argonne National Laboratory
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