[Xastir] Linux turn by turn Navigation/Mapping Software?

[Curt, WE7U]

On Wed, 17 Mar 2004, Derrick J Brashear wrote:

> On Wed, 17 Mar 2004, Jerry Chamberlin wrote:
>
> >
> > Thought, implement gzip to get maps, use the GNIS ?? the one that are all text
> > describing points, they gzip up real nice
>
> GNIS is just names of places, yes? Also, having gzip'd data would make it
> small but not efficient. i have a low-cpu-cycles device, i want efficient,
> not small.

Yea, GNIS supposedly contains all of the labels that are on a 7.5'
topo map, plus the lat/long points to go with them.  That gives you
perhaps a destination point for the routing.  It doesn't give you
the directions regarding how to get there.  It also falls flat on
its face if you're trying to go from street address to street
address, because those points aren't in the GNIS database.

It's a hard problem to solve.  It could be done by someone that had
some experience in CAD, maps, and graph theory.  We have enough info
in the Shapefile street maps so that an initial attempt could be
made, including speed limits for each road, so you could do the
"shortest path" or the "fastest path" between two or more points.

You'd have trouble routing around construction, and trouble with
one-way streets (which are always changing) and other items that
might not be up-to-date on the maps we use.

You'd also have to compute what the nearest street was to each of
your start/stop/via points.  Even that can be tricky.

I have no time/interest in this right now, but others are more than
welcome to take a stab at it.  It's do-able, but it'll be a bit of
work.  I'll help where I can if someone wants to take this on.

--
Curt, WE7U			    archer at eskimo dot com
Arlington, WA, USA		http://www.eskimo.com/~archer
"Lotto:    A tax on people who are bad at math." -- unknown
"Windows:  Microsoft's tax on computer illiterates." -- WE7U
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