CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Sorry I miss your first email.
In Nef you can use points with cartesian coordinates (but you need exact 
constructions).

Is there a reason preventing you from using
Exact_predicates_exact_constructions_kernel for example?


Sebastien


On 02/03/2012 02:22 AM, erickee wrote:
> Update:  I have not yet resolved this issue.  Furthermore, I have found that
> multiplying my homogenous points by a large number causes problems.
>
> If I multiply by 1000, I frequently have overflow issues, even though I am
> using ring type long, which I thought would have a sufficient range to work
> with my typically small homogeneous points (e.g. [1000 1000 1000]).
>
> On the other hand, if I multiply by only 10, I don't have overflow issues,
> but I am throwing away a lot of precision.  For example, a homogenous
> half-plane [1.0  1.04  1.0] has a 46º orientation, but round(10*[1.0 1.04
> 1.0]) has a 45º orientation.
>
> I could use a ring type like CGAL::Gmpz, but I haven't figured out how to
> convert homogenous Gmpz back to a homogeneous double after my computation is
> done.  (I need doubles for post-processing in matlab).
>
> I would greatly appreciate any advice on this topic.
>
> --
> View this message in context: 
> http://cgal-discuss.949826.n4.nabble.com/Converting-doubles-to-Filtered-extended-homogeneous-tp4332165p4353379.html
> Sent from the cgal-discuss mailing list archive at Nabble.com.