[postgis-users] Centroid Calculation Error???

[Martin Davis]

Well, it's not TOO painful - it's mostly a matter of bookkeeping.  But there's a fair bit of that, as you can see from the JTS code.  This code should be in GEOS, so perhaps you can just call it there.

Martin Davis, Senior Technical Architect
Vivid Solutions Inc.
Suite #1A-2328 Government Street   Victoria, B.C.   V8T 5G5
Phone: (250) 385 6040 - Local 308      Fax: (250) 385 6046



> -----Original Message-----
> From: chodgson at refractions.net [mailto:chodgson at refractions.net]
> Sent: Tuesday, October 28, 2003 10:21 AM
> To: PostGIS Users Discussion
> Subject: Re: [postgis-users] Centroid Calculation Error???
> 
> 
> Dave,
> 
> The centroid of the surface is NOT the same as the centroid 
> of the points. The 
> centroid of the surface is much more painful to calculate - 
> maybe we will need 
> to use the equivalent GEOS/JTS function to get this right?
> 
> Chris
> 
> Quoting David Blasby <dblasby at refractions.net>:
> 
> > Düster Horst wrote:
> > > In my opinion the distribution of vertex
> > > points shouldn't have an influence of the centroid position.
> > 
> > 
> > OGC defines centroid as::
> > 
> > Centroid( ):Point-The mathematical centroid for this 
> Surface as a Point.
> > The result is not guaranteed to be on this Surface.
> > 
> > I calculate the centroid of the points of the polygon.
> > 
> > dave
> > 
> > 
> > 
> > 
> > 
> > 
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> > 
> 
> 
> 
> 
> 
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