<div dir="ltr"><div>Idan,<br><br>For the part of your question relating to the API: There are two new API calls:<br><br>double proj_lp_dist (const PJ *P, PJ_LP a, PJ_LP b)<br><br></div><div>and<br><br>double proj_lpz_dist (const PJ *P, PJ_LPZ a, PJ_LPZ b)<br><br></div><div>The first returns the geodesic distance between points aand b, the second the length of the hypothenusis of a right angled triangle with base length proj_lp_dist (a,b), and height a.z-b.z, i.e. "the distance between the points if the Earth was flat".<br><br></div><div>The functions are intended for transformation accuracy assessment, and *do not introduce* anything new: Basically, they are calls to Charles' code, with some syntactic sugar, and discarding the two azimuths from the result, just returning the distance.<br></div><div><br></div><div>But while writing this (and in the view of the material merged yesterday, renaming the old style coordinate types by moving them to the PJ_ name space), I notice that these call signatures are actually buggy: Along with two additional distance functions, they are the only place where the old style coordinates pop to the top of the new style API.<br><br>I will file an issue regarding this, and if the other developers agree you will probably see these signatures in the final 5.0.0:<br><br>
<div>double proj_lp_dist (const PJ *P, PJ_COORD a, PJ_COORD b)<br><br></div><div>and<br><br>double proj_lpz_dist (const PJ *P, PJ_COORD a, PJ_COORD b)<br><br><br></div>
<br><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">2018-02-10 9:30 GMT+01:00 Idan Miara <span dir="ltr"><<a href="mailto:idan@miara.com" target="_blank">idan@miara.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div dir="auto">Thanks for the pointers!</div><span class=""><div class="gmail_extra"><br><div class="gmail_quote">On 9 Feb 2018 10:57 am, "Charles Karney" <<a href="mailto:charles@karney.com" target="_blank">charles@karney.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">The new write-up on the geodesic calculations is available at<br>
<br>
<a href="http://proj4.org/geodesic.html" rel="noreferrer" target="_blank">http://proj4.org/geodesic.html</a><br>
<br>
This just gives a general discussion of the geodesic problem.<br>
Detailed documentation of the API is at<br>
<br>
<a href="https://geographiclib.sourceforge.io/1.49/C/geodesic_8h.html" rel="noreferrer" target="_blank">https://geographiclib.sourcefo<wbr>rge.io/1.49/C/geodesic_8h.html</a><br>
<br>
proj 5.0 introduces no changes to this API on in the performance<br>
of the geodesic code.<br>
<br>
--Charles<br>
<br>
On 02/09/2018 02:15 AM, Idan Miara wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi,<br>
<br>
I read that there was a complete rewrite of the documentation section on geodesic calculations.<br>
<br>
Were all the changes in v5 regarding coordinate transformations?<br>
Or was there any change in API or in performance of geodesic calculations in v5?<br>
<br>
Regards,<br>
Idan<br>
<br>
</blockquote>
</blockquote></div></div>
</span></div>
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