Обсуждение: Box operation algorithms

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Box operation algorithms

От
"Andy Farrell"
Дата:
REGARDING                Box operation algorithms

Hello,

I was wondering if the algorithms used to implement the operations on
box/polygon/point datatypes are documented and available anywhere on the web?

TIA,
Andy


Re: [HACKERS] Box operation algorithms

От
"Thomas G. Lockhart"
Дата:
> I was wondering if the algorithms used to implement the operations on
> box/polygon/point datatypes are documented and available anywhere on
> the web?

Use the source, Luke...

                      - Tom

Re: [HACKERS] Box operation algorithms

От
"Eugene Selkov Jr."
Дата:
Andy Farrell wrote:
>
> REGARDING                Box operation algorithms
>
> Hello,
>
> I was wondering if the algorithms used to implement the operations on
> box/polygon/point datatypes are documented and available anywhere on the web?
>
> TIA,
> Andy

Most of geo funcions are one-liners or very small. I think they are easy
to understand. That's probably why no one (yet) felt an urge to document
them. If you have postgres sources, look in
/usr/src/pgsql/src/backend/utils/adt/geo_ops.c and
/usr/src/pgsql/src/backend/utils/adt/geo_selfuncs.c

Essential part of geo_ops.c are input routines dedicated to parsing of
external representations (box_in(), point_in() and friends). You can
safely ignore functions in this file whose names make no sense to you,
unless you find an accidental feature in parsing.

--Gene