CGAL users discussion list

[Jean Pierre Charalambos <>]

Hi!

any thought regarding my conversion issue? I have been not able to fix it :(

Best,

Jean Pierre



On Tue, Feb 17, 2009 at 6:59 PM, Jean Pierre Charalambos
<>
 wrote:
> Hi cgal users,
>
> I'm new to cgal 3.4 and I want to compute the minimal bounding sphere of a 
> set
> of spheres. So I just tried to adapt the min_sphere_of_spheres_d_3.cpp
> example, but I have a problem when trying to convert the sphere types 
> (radius
> and center) to double types. I suppose this is a basic question, but I have
> read the faqs and I googled a lot without success. My code is:
>
> typedef CGAL::Gmpq FT;
> typedef CGAL::Cartesian<FT> K;
> typedef CGAL::Min_sphere_of_spheres_d_traits_3<K,FT> Traits;
> typedef CGAL::Min_sphere_of_spheres_d<Traits> Min_sphere;
> typedef K::Point_3  Point;
> typedef Traits::Sphere  Sphere;
>
> //after checking in the spheres in ms and computing the minimal sphere (just
> like in the example) I attempted the conversion as follows:
>
> radius = CGAL::to_double(ms.radius());
>
> However, I got the following compilation error:
>
> cannot convert 'CGAL::Null_tag' to 'double' in assignment
>
> If I use "typedef double FT" (instead of typedef CGAL::Gmpq FT) and retrieve
> the radius with "radius = ms.radius()" the code compiles (and it actually 
> runs
> perfectly in cgal3.3), but I get the following errror at running time:
>
> terminate called after throwing an instance of 'CGAL::Assertion_exception'
>  what():  CGAL ERROR: assertion violation!
> Expr: -CGAL_IA_MUL(-1.1, 10.1) != CGAL_IA_MUL(1.1, 10.1)
> File: /usr/include/CGAL/Interval_nt.h
> Line: 154
> Explanation: Wrong rounding: did you forget the -frounding-math option if 
> you
> use GCC?
> Aborted
>
> Thank you in advanced for your suggestions,
>
> Jean Pierre
> --
> You don't become a failure until you're satisfied with being one.
>
>