
Boost Users : 
Subject: Re: [Boostusers] [Geometry] Packing algorithm for rtree?
From: Adam Wulkiewicz (adam.wulkiewicz_at_[hidden])
Date: 20141027 06:57:04
Jeremy Murphy wrote:
> On 27 October 2014 00:34, Adam Wulkiewicz <adam.wulkiewicz_at_[hidden]
> <mailto:adam.wulkiewicz_at_[hidden]>> wrote:
>
> Hi,
>
> Jeremy Murphy wrote:
>
>
> I see that a fourth node splitting algorithm for bulk loading
> is documented in the Introduction to spatial indexes but not
> listed elsewhere (such as Creation and Modification).
> Is it hiding in the library somewhere or is the introduction
> just a tantalizing sneak preview?
>
>
> The packing algorithm is used if the Rtree is created with a
> constructor taking a range e.g. as a pair of Iterators:
>
> http://www.boost.org/doc/libs/1_56_0/libs/geometry/doc/html/geometry/reference/spatial_indexes/boost__geometry__index__rtree/rtree_iterator__iterator_.html
>
> Yes, maybe it should be explicitly stated in the "Creation..."
> section.
>
>
> Ah, fantastic. Hah, turns out I was already using that constructor.
> So what should I write as the second required template parameter,
> which is usually linear<N>, quadratic<N>, etc? Is it just ignored in
> the packing case? If so, that's a bit confusing.
>
Packing algorithm can be and is used if the Rtree is created from some
number of elements. Balancing algorithm is used during splitting of
nodes so e.g. when insert() or remove() is called.
Yes, during inserting, packing algorithm is ignored. Just like during
creation/packing, balancing algorithm is ignored.
Currently there is only one packing algorithm implemented, so there is
no need to pick one like in the case of balancing algorithms. If there
were more then it probably somehow would be possible to pass a group of
parameters.
Regards,
Adam
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