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<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;">Hi Nico,<br>
If the tags are dense or sparse affects the way they are stored in memory or on the hdf5 file;<br>
Sparse tags are kept in pairs <entity handle, value><br>
dense tags are kept in contiguous arrays, corresponding to entity sequences<br>
<br>
I would use dense tags if possible; <br>
On those entities on domains, do you need to identify domains or the value of the tag?<br>
<br>
I mean, are you using the tag for grouping entities or they have the same value ?<br>
<br>
In general, we create sets, and then "tag" them with a tag to identify/classify the sets.<br>
(partition sets, or material sets, etc, which are usually sparse tags)<br>
<br>
If every entity has a different value, you should use a dense tag defined on entities (not on sets)<br>
<br>
If the tags are dense you can access them more efficiently with tag_iterate<br>
<br>
there are some examples here<br>
<br>
<a href="http://ftp.mcs.anl.gov/pub/fathom/moab-docs/DirectAccessWithHoles_8cpp-example.html" target="_blank">http://ftp.mcs.anl.gov/pub/fathom/moab-docs/DirectAccessWithHoles_8cpp-example.html</a><br>
<br>
<a href="http://ftp.mcs.anl.gov/pub/fathom/moab-docs/DirectAccessNoHoles_8cpp-example.html" target="_blank">http://ftp.mcs.anl.gov/pub/fathom/moab-docs/DirectAccessNoHoles_8cpp-example.html</a><br>
<br>
Not sure what you need exactly.<br>
Iulian<br>
<br>
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<div style="direction: ltr;" id="divRpF823921"><font color="#000000" face="Tahoma" size="2"><b>From:</b> moab-dev-bounces@mcs.anl.gov [moab-dev-bounces@mcs.anl.gov] on behalf of Nico Schlömer [nico.schloemer@gmail.com]<br>
<b>Sent:</b> Thursday, April 07, 2016 10:41 AM<br>
<b>To:</b> moab-dev@mcs.anl.gov<br>
<b>Subject:</b> Re: [MOAB-dev] subdomains, sparse tags<br>
</font><br>
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<div dir="ltr">I'm kind of lost here on the tags side anyways. Is there a piece of code that uses tags that I can look at?
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<div>Cheers,</div>
<div>Nico</div>
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<br>
<div class="gmail_quote">
<div dir="ltr">On Thu, Apr 7, 2016 at 3:13 PM Nico Schlömer <<a href="mailto:nico.schloemer@gmail.com" target="_blank">nico.schloemer@gmail.com</a>> wrote:<br>
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<div dir="ltr">Hi everyone,
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<div>I'm just reading up on tags, all starting from the problem that I have mesh on which there are multiple subdomains which may or may not overlap, may or may not fill the the entire mesh. What I will need to do is to set those tags on the mesh and then to
iterate over all entities with that tag (probably multiple times).</div>
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<div>Do I see correctly that sparse tags [1] are the way to go then?</div>
<div><br>
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<div>Cheers,</div>
<div>Nico</div>
<div><br>
</div>
<div>[1] <a href="https://www.mcs.anl.gov/~fathom/moab-docs/html/classmoab_1_1SparseTag.html" target="_blank">https://www.mcs.anl.gov/~fathom/moab-docs/html/classmoab_1_1SparseTag.html</a></div>
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