[mapserver-users] network analysis in mapserver

[Seamus Thomas Carroll]

I am currently using arc/info to solve this problem.  The basic idea is 
take the start point and find its closes node on the road network.  Do the 
same for the destination point.  Now find the shortest distance between 
the two nodes on the road network given an impedance in the dbf.

I have not done any work using postgis to solve this problem.  I have just 
started to explore the possibility.  I was hoping this functionality was 
built into postgis.

seamus


On Fri, 12 Jul 2002, Roberto Micarelli wrote:

> On Friday 12 July 2002 17:27, Robert W. Burgholzer wrote:
> > Seamus,
> > Are you using postGIS by chance? I am working on a set of tools that
> > might not be network analysis, but we may have some overlap that we
> > could share.
> >
> > I too am seeking independence from esri, and postgres extendability (all
> > functions can be written in C, or several other languages) seems to me
> > to be a potential for high quality, open source GIS tools. Already there
> > are several geo-processing routines out there acting in
> > postgres/postgis. What type of analysis functions are you looking for?
> >
> 
> In GRASS we are working at directed graph library (dglib). It is at a early 
> development status, some functions are already implemented (shortest path on 
> digraphs, depth-spanning, minimum-spanning). There are modules from Radim 
> Blazek for steiner-tree and salesman-problem that will be integrated into 
> dglib. The API is still unstable but I'm hardly working on design it.
> Poor documentation... A lot of work to do...
> Maybe we could share some info...
> 
> Roberto
>