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<p>ah ok I jumped too far to conclusion seeing DGGS mentionned. I
read too quickly and am not familiar with HEX9.</p>
<p>Do you plan to submit your work to PROJ upstream?</p>
<p>I don't think it would make sense in the PROJ API to report the
octant number in PROJ_COORD or in WKT, since it isn't needed to
unambiguously qualify a location: just X and Y are sufficient,
right ? So I don't really have a good suggestion to propose to you
to be able to output the octant number. Perhaps there should be a
way in the API to be able to report extra information, specific to
a given projection, but that infrastructure doesn't exist.</p>
<p>Even</p>
<div class="moz-cite-prefix">Le 22/03/2026 à 18:00, Ben Griffin via
PROJ a écrit :<br>
</div>
<blockquote type="cite"
cite="mid:DB6D47D5-AABD-4AAE-8053-CC97039E5559@redsnapper.net">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
Hi Even,
<div>Thank-you for your thoughts.</div>
<div><br>
</div>
<div>As mentioned in my OP, the CRS isn’t a DGGS. It is a
continuous CRS that acts as the backbone for a DGGS.</div>
<div>Consider, please, the net projections that are run using the
current system (albeit via the python module).</div>
<div><br>
</div>
<div><a
href="https://raw.githubusercontent.com/MrBenGriffin/hex9/refs/heads/main/images/rhombus.jpg"
moz-do-not-send="true" class="moz-txt-link-freetext">https://raw.githubusercontent.com/MrBenGriffin/hex9/refs/heads/main/images/rhombus.jpg</a> </div>
<div><br>
</div>
<div>Or</div>
<div><br>
</div>
<div><a
href="https://raw.githubusercontent.com/MrBenGriffin/hex9/refs/heads/main/images/butterfly.jpg"
moz-do-not-send="true" class="moz-txt-link-freetext">https://raw.githubusercontent.com/MrBenGriffin/hex9/refs/heads/main/images/butterfly.jpg</a></div>
<div><br>
</div>
<div>Those are projections under the CRS declared in the OP - they
are not representative of a DGGS.</div>
<div>
<div>I’m not denying that the CRS is related to (and supports)
DGGS - but it is not a DGGS.</div>
</div>
<div><br>
</div>
<div>The query concerned how best to capture a global coordinate
that involves an octahedral scheme - It feels like you picked up
on something else.</div>
<div>One of the aspects of this, which to me feels the most
obvious, is that a CRS is continuous, while a DGGS is not.</div>
<div><br>
</div>
<div>I feel that my position on this is defensible.</div>
<div><br>
</div>
<div>Best regards</div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span>Ben.</div>
<div><br>
</div>
<div>
<div>
<blockquote type="cite">
<div>On 22 Mar 2026, at 16:47, Even Rouault
<a class="moz-txt-link-rfc2396E" href="mailto:even.rouault@spatialys.com"><even.rouault@spatialys.com></a> wrote:</div>
<br class="Apple-interchange-newline">
<div>
<div>Hi Ben,<br>
I don't think PROJ API is the best fit for DGGS
implementations. Probably <a class="moz-txt-link-freetext" href="https://github.com/ecere/dggal">https://github.com/ecere/dggal</a>
would be a better host (I haven't used it myself)<br>
And AFAIK, WKT / ISO-19111 hasn't been designed with
DGGS use cases in mind either.<br>
<br>
Even<br>
</div>
</div>
</blockquote>
</div>
<br>
</div>
<div><br>
</div>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
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</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
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My software is free, but my time generally not.</pre>
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