[postgis-devel] 2.5D TIN Operations

[Darafei "Komяpa" Praliaskouski]

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.

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?



ср, 27 мар. 2019 г. в 20:47, Paul Ramsey <pramsey at cleverelephant.ca>:

> Question that comes to mind: how big are these TINs of which you speak?
>
> 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)
>
> P
>
> On Mar 27, 2019, at 10:02 AM, Darafei Komяpa Praliaskouski <me at komzpa.net>
> wrote:
>
> 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:
>
>  - 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;
>
>  - combine two TINs into a new one defining a lowest part of surface -
> "here is our delivery time map".
>
> I understand the maths of this, but how an API for that can look like? Any
> examples to look at?
>
>
> --
> Darafei Praliaskouski
> Support me: http://patreon.com/komzpa
>
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-- 
Darafei Praliaskouski
Support me: http://patreon.com/komzpa
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