[postgis-users] geos result sets

[Paul Ramsey]

Intersects() *might* work. However, it might be a bit too broad. What 
you want is "interior of A interacts with interior of B". I do not know 
my Relate() function well enough, but there should be a Relate() 
pattern that gives you what you want. Time to haul out your SFSQL and 
read up on the 9 way dimensionally extended model... :)
P.

On Thursday, February 26, 2004, at 01:15 AM, James S reid wrote:

> thanks for that - I can see where you are coming from even if the 
> results
> ends up a little unexpected - interstingly, if you use a distance() = 0
> function you get the 'correct' result so I guess there is some 
> intrinsic
> tolerance in the distance() function?
> one consequence of course is that geometries would need to be very 
> clean to
> prevent this sort of behaviour. Have you any thoughts on what 
> operators I
> could use that would give me the expected result without have to check 
> for
> data inconsistencies ? In practical terms I need to be able to 
> establsih
> containment without the exacting tolerances that geos seems to demand? 
> Will
> the distance function work predicatbly on differnt machine 
> architectures?

      Paul Ramsey
      Refractions Research
      Email: pramsey at refractions.net
      Phone: (250) 885-0632