CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

you must insert in the tree only the keys you have used.

In your examples you are inserting keys 0, 1, 2, 3, 4 and 5.

Try:
>    Tree tree(
>      boost::counting_iterator<std::size_t>(10),
>      boost::counting_iterator<std::size_t>(10+points.size()),
>      Splitter(),
>      Traits(ppmap)
>    );

Sebastien.

On 05/10/2016 05:33 PM, developer wrote:
> I had modified example 3.6.3 to use std::map::insert instead of
> std::map::operator[] but the net effect is the same.
> The sample below with key values of 10 through 15 produces erroneous
> results. If you change the key values to 0, 1, 2, 13, 14, 15 it also
> generates the wrong results. Only key values of 0 through 5 produce the
> correct results.
> My expectation was that any key value should work not just continuous
> integers starting at zero.
> Thank you,
> Michael
>
> #include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
> #include <CGAL/Search_traits_3.h>
> #include <CGAL/Search_traits_adapter.h>
> #include <CGAL/point_generators_3.h>
> #include <CGAL/Orthogonal_k_neighbor_search.h>
> #include <boost/iterator/counting_iterator.hpp>
> #include <utility>
> typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
> typedef Kernel::Point_3 Point_3;
> typedef std::size_t Point;
> typedef boost::const_associative_property_map<std::map<Point,Point_3> >
> My_point_property_map;
>
> typedef CGAL::Search_traits_3<Kernel> Traits_base;
> typedef
> CGAL::Search_traits_adapter<Point,My_point_property_map,Traits_base> Traits;
> typedef CGAL::Orthogonal_k_neighbor_search<Traits> K_neighbor_search;
> typedef K_neighbor_search::Tree Tree;
> typedef Tree::Splitter Splitter;
> typedef K_neighbor_search::Distance Distance;
> int main() {
>    const unsigned int K = 5;
>
>    std::map<Point,Point_3> points;
>
>    points.insert(std::pair<Point,Point_3>(10,Point_3(82.446, 1.432,
> -98.438)));
>    points.insert(std::pair<Point,Point_3>(11,Point_3(82.059, 1.602,
> -98.052)));
>    points.insert(std::pair<Point,Point_3>(12,Point_3(82.059, 1.547,
> -98.469)));
>    points.insert(std::pair<Point,Point_3>(13,Point_3(82.059, 1.384,
> -98.858)));
>    points.insert(std::pair<Point,Point_3>(14,Point_3(82.446, 1.433,
> -97.665)));
>    points.insert(std::pair<Point,Point_3>(15,Point_3(82.059, 1.385,
> -97.246)));
>
>    My_point_property_map ppmap(points);
>    // Insert number_of_data_points in the tree
>    Tree tree(
>      boost::counting_iterator<std::size_t>(0),
>      boost::counting_iterator<std::size_t>(points.size()),
>      Splitter(),
>      Traits(ppmap)
>    );
>    Point_3 query(83.059, 1.384, -98.858);
>    Distance tr_dist(ppmap);
>    // search K nearest neighbours
>    K_neighbor_search search(tree, query, K,0,true,tr_dist);
>    for(K_neighbor_search::iterator it = search.begin(); it !=
> search.end(); it++){
>      std::cout << " d(q, nearest neighbor)=  "
>            << tr_dist.inverse_of_transformed_distance(it->second) << " "
>                << points[it->first] << " " << it->first << std::endl;
>    }
>    return 0;
> }
>
>
>  > -------Original Message-------
>  > From: Sebastien Loriot (GeometryFactory) 
> <>
>  > To: 
>
>  > Subject: Re: [cgal-discuss] dD Spatial Searching using arbitrary keys
>  > Sent: 10 May '16 02:42
>  >
>  > Do you have a minimal compilable example showing what you tried and did
>  > not work?
>  >
>  > Sebastien.
>  >
>  > On 05/10/2016 01:03 AM, developer wrote:
>  > > I am attempting to use the dD spatial searching module using the
> example code in section 3.6.3 (v4.8) as a starting point:
>  > >
> http://doc.cgal.org/latest/Spatial_searching/Spatial_searching_2searching_with_point_with_info_pmap_8cpp-example.html
>  > >
>  > > The data set I'm working with has point ID's (the map key) that do
> not start at zero and are not continuous. However the K_neighbor_search
> function outputs incorrect results for a std::map with integer keys that
> non continuous and/or do not start at zero.
>  > >
>  > > How can I use arbitrary integer keys with the K_neighbor_search
> function? Is the only way to create two maps, one with continuous keys
> for use in the K_neighbor_search and a second to act as a lookup table
> for the actual point ID's?
>  > >
>  > > Thanks,
>  > > Michael
>  > >
>  >
>  >
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