[postgis-users] Oriented BBox Efficient computing?

[Rémi Cura]

Hey DannyD,
I'm afraid I don't understand.
Are you talking about __oriented__ bbox?
Cheers,
Rémi-C

2014-10-23 18:28 GMT+02:00 DannyD <daniel.m.devine at gmail.com>:

> Perhaps already answered, but I start with an empty envelope and use
> 'expandToInclude' successively on each vertex.
> On Oct 23, 2014 7:57 AM, "Håvard Tveite" <havard.tveite at nmbu.no> wrote:
>
>> Search for "Rotating calipers" + width
>>
>> Håvard
>>
>> On 2014-10-23 15:33, Rémi Cura wrote:
>>
>>> Hey list,
>>> somebody has a good idea about how efficiently computing an approximate
>>> oriented bbox for a polygon ?
>>>
>>> The simplest approaches I can think of are
>>>   - iteratively rotate the geom by few degrees, take the envelop. Keep
>>> ration where envelope is min
>>>   - using Principal Components Analysis  : extract points regularly
>>> spaced on border of object,  compute PCA .
>>>
>>> Thanks,
>>> Cheers,
>>> Rémi-C
>>>
>>>
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>>>
>> --
>> Håvard Tveite
>> Department of Mathematical Sciences and Technology, NMBU
>> Drøbakveien 31, POBox 5003, N-1432 Ås, NORWAY
>> Phone: +47 64965483 Fax: +47 64965401 http://www.nmbu.no/imt/
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>
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