[Openstreetmap] Re: [Openstreetmap-dev] openstreetmap roadmap?

[Ben Gimpert]

Hi Ehud,

I'm not sure about the extent of the mathematical gritty-ness of your
merging problem -- but be sure to take a look at the merge* methods in
".../utils/tiger_import/tiger/geometry.rb" that I wrote for cleaning up
the TIGER data. Note that it takes a two "chains" of line segments and
returns a single chain if applicable.

	Ben


On Mon, Jul 25, 2005 at 11:57:43PM +0300, Ehud Shabtai wrote:
> Frank Mohr wrote:
> 
> >Ehud Shabtai wrote:
> > 
> >
> >>On 7/25/05, Tom Carden <tom at tom-carden.co.uk> wrote:
> >>   
> >>
> >>>>The approach I'm thinking of is having a server which will receive GPS
> >>>>tracks,
> >>>>transfer them to road segments and nodes and merge with current map
> >>>>       
> >>>>
> >>>Automatically?  How?
> >>>     
> >>>
> >>Take the GPS traces, split them to segments (by detecting turns,
> >>detecting intersection, etc') and add them as road segments to the
> >>database. If the database already contains a segment near the one we
> >>want to add, do some merging.
> >>   
> >>
> >
> >just this "do some merging" is the problem
> >
> >i tried several approaches to join 2 track segments, but each
> >failed in some cases
> > 
> >
> I don't expect to find a perfect solution. It should produce good 
> results and allow users to correct incorrect merges through an applet.
> 
> As I plan to write this utility would you care to discuss the approaches 
> you tried for doing the merges?
> 
> Ehud.
> 
> >frank