CGAL users discussion list

[Ben Supnik <>]

Hi,

Marco Aurelio Sterpa wrote:
> I've used this definition for numeric type, can the running time depends 
> by this?
>
> typedef CGAL::Exact_predicates_exact_constructions_kernel_with_sqrt    
> Kernel_2;
> typedef Kernel_2::FT                            NT;

Yes and no.  That kernel may be unnecessarily slow...you might get more 
speed with a faster one, but the fundamental O(N^2) of the algorithm 
isn't going to go away even if you use a faster kernel.  I don't think 
any of the kernels have faster than constant-time operations but I am 
not sure about this.  You may want to try a filtered kernel or NT or 
something...for my project I simply tried some common ops with a whole 
range of kernels and picked the fastest one that met my numeric needs 
(exact ctors) as measured on real data. :)