[geos-devel] Issues with relate not handling GeometryCollections?

[Martin Davis]

I've thought about this too, and I suppose that the more reasonable definition of robust is "robust => correct".

That then raise the issue of: What does "correct" mean in the context of spatial functions which can only be computed as approximations (such as buffer and the overlay functions)?   

I suppose the answer is to define some sort of tolerance area by which the returned answer can differ from the exact answer.  The problem here is that currently we have no way of verifying whether or not answers are "correct" ( = within tolerance) since we have no way of calculating or expressing the *exact* answer!

Martin Davis, Senior Technical Specialist
Vivid Solutions Inc.
Suite #1A-2328 Government Street   Victoria, B.C.   V8T 5G5
Phone: (250) 385 6040    Fax: (250) 385 6046
EMail: mbdavis at vividsolutions.com  Web: www.vividsolutions.com


> -----Original Message-----
> From: Paul Ramsey [mailto:pramsey at refractions.net]
> Sent: Friday, December 06, 2002 2:00 PM
> To: GEOS Development List
> Subject: Re: [geos-devel] Issues with relate not handling
> GeometryCollections?
> 
> 
> Martin Davis wrote:
> > semantical note: can code be called robust it it's incorrect?).    
> 
> Well, not in the limit, since then my robust Buffer function 
> could look 
> like this:
> 
> public Geometry Buffer(Geometry geom) {
> 	return geom;
> }
> 
> 
> As a side note, I have noticed our backups go way faster now 
> that I have 
> directed all the output to /dev/null instead of /dev/mt0 :)
> 
> -- 
>        __
>       /
>       | Paul Ramsey
>       | Refractions Research
>       | Email: pramsey at refractions.net
>       | Phone: (250) 885-0632
>       \_
> 
> 
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