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Nyall,
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<div class="">that would be a very welcome addition to QGIS! Let me know if I can be of assistance to you in that regard (I suspect documentation might be the biggest issue…).
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<div class="">Calvin,</div>
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<div class="">The functionality that PROJ exposes from GeographicLib is seen in the geodesic.h header [0]. I am not entirely sure that it’s a one to one representation of the standalone version of the library but I think so. If there’s is something that you
need that is missing let me know and I’ll see what I can do about it for the next release of PROJ.</div>
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<div class="">On a related note, I have been meaning to raise a similar issue based on QGIS’s not so accurate polygon-area-on-the-ellipsoid calculations. A colleague of mine came across some differences between QGIS and CARIS LOTS while doing area calculations
in relation to a border dispute at sea. After that I tested several popular closed source GIS apps and they all performed better than QGIS. I would have loved to use QGIS to solve this problem but unfortunately had to go with one of the other applications
for this. Basing qgsdistancearea.[cpp|h] (probably other ones as well) on GeographicLib should sort that out and bring QGIS at the top of the game :-)<br class="">
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<div>/Kristian</div>
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<div>[0] <a href="https://github.com/OSGeo/proj.4/blob/master/src/geodesic.h" class="">https://github.com/OSGeo/proj.4/blob/master/src/geodesic.h</a></div>
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<div class="">On 25 Sep 2018, at 01:25, Nyall Dawson <<a href="mailto:nyall.dawson@gmail.com" class="">nyall.dawson@gmail.com</a>> wrote:</div>
<br class="Apple-interchange-newline">
<div class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">On
Tue, 25 Sep 2018 at 06:49, C Hamilton <</span><a href="mailto:adenaculture@gmail.com" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class="">adenaculture@gmail.com</a><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">>
wrote:</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">
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Nyall,<br class="">
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Thanks for your confidence and encouragement. I would be interested, but don't know where to begin. Shape Tools relies on geographiclib which is slightly more accurate than Vincinty. Geographlib is not a library that is included with the OSGeo distribution.
However, as of the past several years Proj.4 makes use of geographiclib. I am guessing QGIS has not exposed any of proj.4's geographiclib routines and I don't know how much of geographiclib Proj.4 actually uses. Including geographiclib could open up future
opportunities of using some of the Earth's gravity models which are even more accurate for measuring distances. Using the C++ geographiclib libraries in the QGIS core would be faster than python only code.<br class="">
<br class="">
For me to even begin, I need geographiclib as part of the QGIS core. If there is a path to accomplish this, then we can discuss further details on what and how to migrate Shape Tools functionality into core.<br class="">
</blockquote>
<br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">
<span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">That
should be relatively straightforward. I can do this after 3.4 is</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">
<span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">released
and feature freeze is lifted. Remind me after this :)</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">
<br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">
<span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Nyall</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">
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Calvin<br class="">
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<blockquote type="cite" class="">If you have any suggestions I would welcome them.<br class="">
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Shape Tools is fantastic, and plugs a much needed gap in QGIS core<br class="">
functionality. Lovely work!<br class="">
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Can I strongly encourage you to investigate porting some of these<br class="">
features/fixes over to QGIS core? You've obviously got the talent and<br class="">
knowledge to do so, and it'd be great to offer this functionality<br class="">
out-of-the-box. I'm available for mentoring if you need assistance<br class="">
with QGIS core development/build setup/general c++ help!<br class="">
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Nyall<br class="">
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<span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">_______________________________________________</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">
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