[Ns-developers] [ns3] Vector and different coordinates system

[Federico Guerra]

>Federico, would you mind clarifying above what you now plan to do 
>(described above) as the bare minimum vs. what you view as ideal?

>I'm sensing from the above that you are not planning to introduce 
>SphericalMobilityModel but just develop a cartesian version of what you 
>need. 


Hi Tom, 
I think I'll stick to the plan and implement some kind of MobilityModel (waypoint, maybe constant velocity).
Maybe some PositionAllocator. All based on Vector (cartesian). Do we all agree on that?
I'll let you know if the conversion error becomes an issue.

> The ideal solution, since I have to rewrite the mobilitymodel, and since
> this models would work only with geographical coords (or spherical coords),
> would be to introduce, as Mathieu already pointed out, a new
> SphericalMobilityModel base class, that extends MobilityModel, and that
> introduces something like:
>
> virtual SphericalVector GetPosition( ) = 0;
>

> and make all the new MobModels inherit and implements this new function.

This implementation was actually an idea, but I suppose that in your vision this would be some kind of code bloat and can't be approached. Am I wrong?


As a last note:
keep in mind that it will take me some time to implement any solution we agree on, since I have already a primary job.
The WOSS integration into NS3 project is a part-time collaboration that i have with University of Padua!

Cheers,

Federico Guerra


________________________________
 Da: Tom Henderson <tomh at tomh.org>
A: Federico Guerra <fedwar82 at yahoo.it> 
Cc: Pavel Boyko <boyko at telum.ru>; mathieu <mathieu at cutebugs.net>; Nicola Baldo <nbaldo at cttc.es>; "ns-developers at ISI.EDU" <ns-developers at ISI.EDU> 
Inviato: Venerdì 20 Aprile 2012 7:45
Oggetto: Re: [Ns-developers] [ns3] Vector and different coordinates system
 
On 04/19/2012 11:05 AM, Federico Guerra wrote:
> Hi Tom,
> I also fear that the mobilityModel could be really coupled with the
> coordinate system.
>
> In geographical coords (or spherical coords, is the same) even a simple
> model that makes you move
> from point A to point B at the same altitude (so along the same
> spherical surface) should not use the standard cartesian distance, but
> would use the
> distance along a great circle.
>
> As Nicola pointed out before even a simple rectangle position allocator
> won't work that well with geographical coords.
>
> I think that this example could be found for other coordinates as well.
>
> So I think that the easiest solution would be to stick with Vector,
> since I would have to rewrite the most of the MobilityModels anyway.
> Actually for the first version I would write the bare minimum, and I
> would add new models in the future.
>
> The ideal solution, since I have to rewrite the mobilitymodel, and since
> this models would work only with geographical coords (or spherical coords),
> would be to introduce, as Mathieu already pointed out, a new
> SphericalMobilityModel base class, that extends MobilityModel, and that
> introduces something like:
>
> virtual SphericalVector GetPosition( ) = 0;
>
> and make all the new MobModels inherit and implements this new function.
> But I agree that this solution would be a code bloat.

Federico, would you mind clarifying above what you now plan to do 
(described above) as the bare minimum vs. what you view as ideal?

I'm sensing from the above that you are not planning to introduce 
SphericalMobilityModel but just develop a cartesian version of what you 
need.

- Tom