[mlpack] Numeric sensitivity of RangeSearch

[Li Dong]

Hi Ryan,

Thanks for your quick fixing! It looks correct now. The tutorial is the key resources for our users~ It would be better if you could give some explanation for this change on the tutorial.

Best,

Li

On Mar 25, 2014, at 10:06 PM, Ryan Curtin <gth671b at mail.gatech.edu> wrote:

> On Tue, Mar 25, 2014 at 09:55:17PM +0800, Li Dong wrote:
>> Dear Ryan,
>> 
>> I have isolated a bug case into a single code in the attachment, from which you can see the results:
>> 
>> Neighbor grid number is 201 when R is 1.
>> Neighbor grid number is 102 when R is 6.371e+06.
> 
> Hi Li,
> 
> Thank you for the easy code sample.  In the code you have written:
> 
>  typedef mlpack::tree::BinarySpaceTree<
>      mlpack::bound::HRectBound<2>,
>      mlpack::range::RangeSearchStat> TreeType;
>  typedef mlpack::metric::SquaredEuclideanDistance MetricType;
>  typedef mlpack::range::RangeSearch<MetricType, TreeType> Searcher;
> 
> If you change SquaredEuclideanDistance to EuclideanDistance, the problem
> is solved.  I noticed that the tutorial [1] suggests using the
> SquaredEuclideanDistance class, but this is no longer correct based on
> the pruning rules that the RangeSearch class uses.
> 
> I have fixed the tutorials in r16378 and r16379 and am in the process of
> rebuilding them for the website.  I am sorry for the errors in the
> tutorials.
> 
> Thanks,
> 
> Ryan
> 
> -- 
> Ryan Curtin    | "I am."
> ryan at ratml.org |   - Joe