Re: geometry: knn search of point to many linestrings?

From: Adam Wulkiewicz (adam.wulkiewicz_at_[hidden])
Date: 2021-06-14 11:09:37

W dniu 14.06.2021 o 12:26, Jens Thiele pisze:
> Adam Wulkiewicz via Boost-users <boost-users_at_[hidden]> writes:
>
>> Without knowing your code I can't esstimate if this is long time or
>> not, I can only guess. In general qbegin() loop gathering some number
>> of nearest elements should take similar time to query() call doing the
>> same. So you can try getting some number of knn boxes from the R-tree
>> and checking if this is the case.
> it looks like I have some fundamental misunderstanding here:
> t->qbegin(idx::nearest(pt, 100)) is really fast (<1ms) but
> t->qbegin(idx::nearest(pt, tree_size)) with tree_size=37133 is really
> slow (~500ms)
>
> shouldn't those calls take approximately the same time? I thought the
> search is done incrementally?

Yes, this doesn't look right. I have to look into this.
Would you mind creating an issue at github?

Adam