--- Lun 17/8/09, Mark Burton <markb@ordern.com> ha scritto:

Da: Mark Burton <markb@ordern.com> Oggetto: Re: [mkgmap-dev] R:  Progressing patches A: mkgmap-dev@lists.mkgmap.org.uk Data: Lunedì 17 agosto 2009, 11:28

Hi Marco,

...

Hi Mark, I did not follow very well last discussions. I agree in enabling remove-short-arcs by default, but with no min length (i.e. min lenght=0).

Could you please explain why arcs shorter than 5m should be collapsed?

Arc lengths appear to be encoded in units of 16 feet. That is equal to approx 4.8m. i.e. an arc that is less than 4.8m is encoded as length 0. So if we want all arcs to have a non-zero length, they must be at least 4.8 metres, rounding up to an integer gives 5m.

Very strange about the 16 feet units. As far as I kew garmin utilizes MKSA And even if the 16feet units is true, maybe during the encoding a rouding is appied: - an arc <2.4m is encoded as zero 16feet units - between 2.5m and 7.6m is one 16feet units. - etc. At last, in my experience with mkgmap never had problems with --remove-short-arcs without min arc length (i.e. remove only zero length arcs) Ciao, Marco.

Personally, I am not convinced that having zero length arcs really makes a difference. However, some people report that the minimum length needs to be greater than 0 otherwise routing is broken in some places.

Cheers,

Mark _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev