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<p>for all practical purposes, it seems to be one. I don't know why
it hasn't been formally tagged as such in EPSG. I see that back in
times I added in <a class="moz-txt-link-freetext" href="CoordinateMetadata::create()">CoordinateMetadata::create()</a> an exception to
check if a CRS had a point motion operation attached to it to
allow it to be used to create a CoordinateMetadata object</p>
<div class="moz-cite-prefix">Le 01/03/2026 à 23:46, Javier Jimenez
Shaw a écrit :<br>
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<blockquote type="cite"
cite="mid:CADRrdKvqqNR3DhY0OhWRqTjN57m96r+MWDd5uBT9TKmrC6F=OA@mail.gmail.com">
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<div>In your last PR <a
href="https://github.com/OSGeo/PROJ/pull/4685/"
moz-do-not-send="true" class="moz-txt-link-freetext">https://github.com/OSGeo/PROJ/pull/4685/</a>
you use "NAD83(CSRS)v7" as an example, but it does not have a
dynamic datum. The datum is type
3, PJ_TYPE_GEODETIC_REFERENCE_FRAME.</div>
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<br>
<div class="gmail_quote gmail_quote_container">
<div dir="ltr" class="gmail_attr">On Sun, 22 Feb 2026 at 18:32,
Even Rouault <<a href="mailto:even.rouault@spatialys.com"
moz-do-not-send="true" class="moz-txt-link-freetext">even.rouault@spatialys.com</a>>
wrote:<br>
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style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br>
Le 22/02/2026 à 15:28, Javier Jimenez Shaw via PROJ a écrit :<br>
> Hi<br>
><br>
> the C function proj_coordinate_metadata_create can<br>
> <a
href="https://proj.org/en/stable/development/reference/functions.html#c.proj_coordinate_metadata_create"
rel="noreferrer" target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://proj.org/en/stable/development/reference/functions.html#c.proj_coordinate_metadata_create</a><br>
> allows to create a dynamic system with an epoch.<br>
><br>
> In case the crs is not dynamic, it fails and emits an
error.<br>
> However I do not see how to check if a system is dynamic,
to call it <br>
> only if really needed.<br>
><br>
> Is there such a function in the C API?<br>
<br>
checking proj_get_type() ==
PJ_TYPE_DYNAMIC_GEODETIC_REFERENCE_FRAME on <br>
the result of proj_crs_get_datum()<br>
<br>
-- <br>
<a href="http://www.spatialys.com" rel="noreferrer"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">http://www.spatialys.com</a><br>
My software is free, but my time generally not.<br>
<br>
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<pre class="moz-signature" cols="72">--
<a class="moz-txt-link-freetext" href="http://www.spatialys.com">http://www.spatialys.com</a>
My software is free, but my time generally not.</pre>
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