Re: sdo_geom.sdo_area gives negative areas

From: Shakespeare <>
Date: Fri, 9 May 2008 08:40:45 +0200
Message-ID: <4823f1ec$0$14353$>

"Jens Müller" <> schreef in bericht
> Hi,
> I used the sdo_geom.sdo_area function on some polygons in my database.
> The result is a negative number, the absolute value seems to be right.
> At a first glance, I did not find anything on this in the docs. Is this
> maybe due to a wrong direction (clockwise vs. counter-clockwise) of the
> points?
> If so, is this "bad" apart from the negative area values?

Yes, wrong direction is is bad. When your geometry is in the wrong direction, it is a 'hole' or a 'donut'. You will encounter problems calculating overlaps etc. About the negative area: I can't recall this has anything to do with the direction. What tolerance do you use?

Shakespeare Received on Fri May 09 2008 - 01:40:45 CDT

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