<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Well Olivier cadged the idea of a TIN type from a SQL/MM discussion paper I think, which never went anywhere. I don’t know if it had any ST_Functions elabourated in it for analysis (almost certainly: not) but it might provide some language around the edges.<div class=""><br class=""></div><div class="">P<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Mar 27, 2019, at 10:55 AM, Darafei Komяpa Praliaskouski <<a href="mailto:me@komzpa.net" class="">me@komzpa.net</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">As a datapoint, a TIN on top of all the roads in Belarus is around 600MB, which fits into Postgres tuple. A city-wide one is below a hundred megabytes, which I believe fits into memory.<br class=""><br class="">ST_Something was my thought too, but question I have in mind is more about naming: are there names for these operations already, is there a wider list of them somewhere?<br class=""><br class=""><br class=""></div><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">ср, 27 мар. 2019 г. в 20:47, Paul Ramsey <<a href="mailto:pramsey@cleverelephant.ca" class="">pramsey@cleverelephant.ca</a>>:<br class=""></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word;line-break:after-white-space" class="">Question that comes to mind: how big are these TINs of which you speak?<div class=""><br class=""></div><div class="">I mean, we have a TIN object now, but as with POLYGON and LINESTRING, the expectation is that the TIN fits in-memory. Which means the API is pretty simple, no? Just ST_Something(TIN) returns POLYGON. ST_Union(TIN, TIN) returns TIN? I mean, write out your list of functions, and what they do, I cannot imagine they’ll be too terrible. It only gets terrible when we need to model something larger than memory (ala topology)</div><div class=""><br class=""></div><div class="">P</div><div class=""><div class=""><br class=""><blockquote type="cite" class=""></blockquote></div></div></div><div style="word-wrap:break-word;line-break:after-white-space" class=""><div class=""><div class=""><blockquote type="cite" class=""><div class="">On Mar 27, 2019, at 10:02 AM, Darafei Komяpa Praliaskouski <<a href="mailto:me@komzpa.net" target="_blank" class="">me@komzpa.net</a>> wrote:</div><br class="m_-8077527463659529958Apple-interchange-newline"></blockquote></div></div></div><div style="word-wrap:break-word;line-break:after-white-space" class=""><div class=""><div class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="">Let's imagine I have a bunch 2.5D TINs representing some measurement - say, a travel time to a central point. I want to perform operations on top of these:<br class=""><br class=""></div><div class=""> - for each TIN in the group I would like to get a 2D polygon of bounds where it is the lowest in the group - "here is delivery area for this office" if you wish;</div><div class=""><br class=""></div><div class=""> - combine two TINs into a new one defining a lowest part of surface - "here is our delivery time map".<br class=""><br class="">I understand the maths of this, but how an API for that can look like? Any examples to look at?<br class=""><br class=""><br class=""></div></div>-- <br class=""><div dir="ltr" class="m_-8077527463659529958gmail_signature" data-smartmail="gmail_signature"><div dir="ltr" class="">Darafei Praliaskouski<br class="">Support me: <a href="http://patreon.com/komzpa" target="_blank" class="">http://patreon.com/komzpa</a></div></div></div></blockquote></div></div></div><div style="word-wrap:break-word;line-break:after-white-space" class=""><div class=""><div class=""><blockquote type="cite" class=""><div class="">
_______________________________________________<br class="">postgis-devel mailing list<br class=""><a href="mailto:postgis-devel@lists.osgeo.org" target="_blank" class="">postgis-devel@lists.osgeo.org</a><br class=""><a href="https://lists.osgeo.org/mailman/listinfo/postgis-devel" target="_blank" class="">https://lists.osgeo.org/mailman/listinfo/postgis-devel</a></div></blockquote></div><br class=""></div></div>_______________________________________________<br class="">
postgis-devel mailing list<br class="">
<a href="mailto:postgis-devel@lists.osgeo.org" target="_blank" class="">postgis-devel@lists.osgeo.org</a><br class="">
<a href="https://lists.osgeo.org/mailman/listinfo/postgis-devel" rel="noreferrer" target="_blank" class="">https://lists.osgeo.org/mailman/listinfo/postgis-devel</a></blockquote></div>-- <br class=""><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr" class="">Darafei Praliaskouski<br class="">Support me: <a href="http://patreon.com/komzpa" class="">http://patreon.com/komzpa</a></div></div>
_______________________________________________<br class="">postgis-devel mailing list<br class=""><a href="mailto:postgis-devel@lists.osgeo.org" class="">postgis-devel@lists.osgeo.org</a><br class="">https://lists.osgeo.org/mailman/listinfo/postgis-devel</div></blockquote></div><br class=""></div></body></html>