Point inside/outside area constructed by an expanded path
| От | Josi Perez (3T Systems) |
|---|---|
| Тема | Point inside/outside area constructed by an expanded path |
| Дата | |
| Msg-id | AANLkTim6gLxH5G37N+==6Lija4DnNYmb-d6FWED9-R7s@mail.gmail.com обсуждение исходный текст |
| Ответы |
Re: Point inside/outside area constructed by an expanded
path
Re: Point inside/outside area constructed by an expanded path |
| Список | pgsql-general |
Hi,
I use postgreSQL.8.4.2 and don't have postGIS installed.
I have a geometric type polygon and I know that it is possible to determine if a point it is inside or not of this polygon, using anything like that:
select polygon('(-23.5672,-46.6510),(-23.5670,-46.65095),(-23.5672,-46.6508),(-23.5672,-46.6510)') @> point('-23.567534,-46.64942')
The question:
Anyone knows an algorithm or have ideas how to determine if a point it is inside an area constructed by geometric type path expanded for a known distance?
Graphically:
the path
x=========x=======x
the path expanded by a distance
| | A |
| | |
-------x=========x=======x------- C
| | |
B | | |
the points A and B are inside and the point C are outside .
Suggestions are welcome.
Thanks in advance,
Josi Perez
#avg_ls_inline_popup { position:absolute; z-index:9999; padding: 0px 0px; margin-left: 0px; margin-top: 0px; width: 240px; overflow: hidden; word-wrap: break-word; color: black; font-size: 10px; text-align: left; line-height: 13px;}
I use postgreSQL.8.4.2 and don't have postGIS installed.
I have a geometric type polygon and I know that it is possible to determine if a point it is inside or not of this polygon, using anything like that:
select polygon('(-23.5672,-46.6510),(-23.5670,-46.65095),(-23.5672,-46.6508),(-23.5672,-46.6510)') @> point('-23.567534,-46.64942')
The question:
Anyone knows an algorithm or have ideas how to determine if a point it is inside an area constructed by geometric type path expanded for a known distance?
Graphically:
the path
x=========x=======x
the path expanded by a distance
| | A |
| | |
-------x=========x=======x------- C
| | |
B | | |
the points A and B are inside and the point C are outside .
Suggestions are welcome.
Thanks in advance,
Josi Perez
В списке pgsql-general по дате отправления: