Kevin Neufeld schrieb:
Unless I misunderstand what you are after, why don't you simply expand
the bounding box of the point by your required amount?
ie.
SELECT
ST_AsText(geom),
ST_AsText(ST_Expand(geom, 2))
FROM (SELECT 'POINT(5 5)'::geometry AS geom) AS a;
st_astext | st_astext
------------+--------------------------------
POINT(5 5) | POLYGON((3 3,3 7,7 7,7 3,3 3))
(1 row)
-- Or create a rectangle from a point
SELECT
ST_AsText(geom),
ST_AsText(
ST_Envelope(ST_MakeLine(
ST_MakePoint(ST_X(geom) - 3, ST_Y(geom) - 2),
ST_MakePoint(ST_X(geom) + 3, ST_Y(geom) + 2)
))
)
FROM (SELECT 'POINT(5 5)'::geometry AS geom) AS a;
st_astext | st_astext
------------+--------------------------------
POINT(5 5) | POLYGON((2 3,2 7,8 7,8 3,2 3))
(1 row)
-- Kevin
Daniel Grum wrote:
Dear Mailing-List,
I want to create a square/rectangle around a point-->via
box2d(geometry) or buffer(geometry, double precision) for example.
If I have this rectangle I want to intersect this with another
polygon--> saved in the (geodata) table: wald_by column: the_geom, to
get information about the area the the "lumberjack" can dig.
The point in the middle of the rectangle = the point that is saved in
a table in my database in the table: holzfaeller in the column the_geom!
Is this possible to solve?
Do I have to save this calculated square/rectangle in an extra/own
table?
Thanks for every help.
Daniel
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Your request nr.2 is perfect, thank you.
But can use this created polygon to selcet a part of another polygon, in
my case public.wald_by.the_geom.
Or do I have to save the selcted information in a table and use this for
the new request???
Because I need to selcet the other polygon to calculate the area of the
selected part, of public.wald_by.the_geom !
--Daniel
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