[Qgis-developer] intersect error

Carson Farmer carson.farmer at gmail.com
Tue Jan 27 08:48:47 EST 2009


Martin,
> But I see some reasons why you shouldn't do it like this:
> 1. efficiency - for single-part geometries this would mean one more
> copy of geometry (+ conversion from QList to python list)
> 2. compatibility - ordinary users of qgis v1.0 won't have
> asGeometryCollection() available
> 3. destruction of geometries - I can't seem to find a way how to
> convince SIP to transfer ownership of new geometries in the list to
> python. So, while it works, there are leaked geometries after every call
>   
Yes, I noticed this [3] last night after I tried adding it myself. 
Efficiency [1] is also a problem, and I noticed a significant speed 
decrease when I implemented it in practice. Compatibility [2] is also an 
issue, though perhaps less critical than the other two, as I can always 
check to see what version of QGIS someone is using...

Hmm, any other possible solutions? What about the rest of the devs: any 
ideas?

Thanks for your work on this so far Martin,

Carson

-- 
Carson J. Q. Farmer
ISSP Doctoral Fellow
National Centre for Geocomputation (NCG),
Email: Carson.Farmer at gmail.com
Web:   http://www.carsonfarmer.com/
       http://www.ftools.ca/




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