Hi,
If I have an Oracle table with an SDO_GEOMETRY column, and I insert a
point into it - example:
MDSYS.SDO_GEOMETRY(2001, 8307, NULL, MDSYS.SDO_ELEM_INFO_ARRAY(1, 1,
1), MDSYS.SDO_ORDINATE_ARRAY(-82.90755596903085, 42.40409951227155))
Then I can use the SDO_GEOM.SDO_BUFFER function to get a buffer around
it (and specify the units in miles) ->
// 1.5 miles, 0.5 tolerance
SELECT SDO_GEOM.SDO_BUFFER(a.geometry, 1.5, 0.5, 'unit=mile') geom
FROM MY_TABLE a.id = 1;
Simple enough, but how do I do the same thing in JTS? If I try the following:
Geometry point = new WKTReader().read("POINT(-82.90755596903085
42.40409951227155)");
// question1: should I set the SRID? Oracle uses 8307 for WGS:84, but
JTS seems to ignore SRID in calculations, is this true?
// question2: what units does buffer take? I make the assumption of
meters, but this is wrong
// try converting 1.5 miles to meters
double meters = 2414.016
Geomtry buffer = point.buffer(meters);
This is very wrong since it gives me polygon with coordinates that are
outside -180/180, -90/90. Do I assume then that buffer takes radians
I guess?
I'm just trying to accomplish the same thing I can do in Oracle above with JTS.
Thanks in advance,
Davis
--
Zeno Consulting, Inc.
home: http://www.zenoconsulting.biz
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