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Hello Christian<br>
<div class="moz-cite-prefix"><br>
Le 20/11/13 11:05, Christian Gendreau a écrit :<br>
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<blockquote
cite="mid:CA+V8i47tHdu9WPwXbuNcN=u6ERT14XZnozPuc_=Dfy2JQpZnmg@mail.gmail.com"
type="cite">
<pre wrap="">I can confirm that using PRIMEM in gradians I'm getting :
POINT (2.4173355764792475 48.83520898436396)
Which seems to be exact.</pre>
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Thanks for the confirmation.<br>
<br>
<blockquote
cite="mid:CA+V8i47tHdu9WPwXbuNcN=u6ERT14XZnozPuc_=Dfy2JQpZnmg@mail.gmail.com"
type="cite">
<pre wrap="">So my next question is, how can I be aware of that?
There is no unit directly associated with PRIMEM and the definition of
spatialreference.org
(<a class="moz-txt-link-freetext" href="http://spatialreference.org/ref/epsg/27572/ogcwkt/">http://spatialreference.org/ref/epsg/27572/ogcwkt/</a>) is using degrees.
</pre>
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The only way I can imagine is to be aware of who is the WKT
producer, and adapt accordingly:<br>
<br>
<ul>
<li>If the producer is GDAL, PostGIS or ERSI, then units are
degrees.</li>
<li>If the producer is GeoTools, Apache SIS or Cadcorp (I presume,
since they are the spec. author), then units are those of the
enclosing GEOGCS element.</li>
<li>I don't know for Oracle WKT...</li>
</ul>
<p><br>
Frank Warmerdam wrote a page of WKT issues at [1]. Some of the
variations that we observe in WKT interpretations are also listed
at [2]. Those problems are one of the main motivations why OGC/ISO
started a "WKT 2" effort. A "WKT 2" specification is close to
final stage and is expected to be available as the international
standard ISO 19162. It would hopefully solve the problems that we
currently see with WKT 1.<br>
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<p> Martin<br>
<br>
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<p>[1] <a class="moz-txt-link-freetext" href="http://home.gdal.org/projects/opengis/wktproblems.html">http://home.gdal.org/projects/opengis/wktproblems.html</a><br>
[2]
<a class="moz-txt-link-freetext" href="https://builds.apache.org/job/sis-jdk7/site/apidocs/org/apache/sis/io/wkt/Convention.html#OGC">https://builds.apache.org/job/sis-jdk7/site/apidocs/org/apache/sis/io/wkt/Convention.html#OGC</a><br>
<br>
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