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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Nyall,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">For 1, try giving proj_pj_info() a go. I am not sure that it will work in all situations (a compound CRS will probably
not behave as you might want/expect). There’s currently not a similar function for retrieving the ellipsoid id, but it can be added to proj_pj_info() if needed. You are welcome to submit a PR with such a change (if you are quick it can be part of 6.1.0).<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">/Kristian<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Fra:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> PROJ <proj-bounces@lists.osgeo.org>
<b>På vegne af </b>Nyall Dawson<br>
<b>Sendt:</b> 3. maj 2019 03:38<br>
<b>Til:</b> PROJ <proj@lists.osgeo.org><br>
<b>Emne:</b> [PROJ] Getting "proj" and "datum" for a CRS<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Hi list,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Next question:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">If I have a crs created from a proj string like:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">+proj=tmerc +lat_0=0 +lon_0=102 +k=0.9999 +x_0=500000 +y_0=0 +ellps=WGS84 +units=m +no_defs +type=crs<o:p></o:p></p>
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<p class="MsoNormal">1. How can I get the "tmerc" acronym from the proj API? If I call proj_crs_get_coordoperation and then proj_coordoperation_get_method_info I can retrieve the method name, but this is a long version of this value (ie. ."Transverse Mercator",
not the tmerc acronym)<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">2. How can I get the ellipsoid/datum value? Again, I can call proj_get_ellipsoid to get an ellipsoid, and from that I've been using proj_get_id_auth_name/proj_get_id_code. But this only sometimes gives a value, and ideally I'm trying to
retrieve the "WGS84" value used in the original proj string.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">(I'm trying to use the official proj methods to retrieve these values - without resorting to regex parsing)<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">3. Using proj_as_proj_string sometimes results in errors like: "proj_as_proj_string: Unsupported conversion method: Lambert Conic Conformal (West Orientated)". I'm guessing this indicates that there's NO way of representing that projection
using proj strings, and I'm wasting my time if I try to work around this?<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Nyall<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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