Hi,

Good news.

For me, what was missing for the moment with spatial tasks was something
that could coerce linear spatial objects to (i)graph objects so as to pull
out all the potentiel of igraph package.

I can remember some attempts by Barry Rownlingson with a buildTopo function
http://rpubs.com/geospacedman/routing

What I find constraining in the SpatialLinesNetwork function is that it
only accepts singleLine SpatialLines objects, althoug the fact is that the
spatial data we'll use will mainly be composed of roads, rivers, etc...that
aren't, natively, single lines

Maybe we could suggest a function that "explodes" multi-line SpatialLines
objects while preserving the attributes (since the attributes can drive
some graph analysises)

Also, one more thing I think of is snapping: let's suppose I have two
points representing buildings and I'd like to compute the shortest path
between them. With spatstat, we can get the edge connecting the node (the
building) to the network, so we're not far from executing the graph stats.

To sum up, I'd sugget:
- accepting multi-line SpatialLines objects
- building a new network given extra/outer nodes

For the moment, to do the basic graph stats, I'd still use GRASS . I would
be happy to do all this stuff with R. And I think we're really not that far
from that..



2013/6/25 Forrest Stevens <forrest@ufl.edu>

> Hi Edzer, this is definitely very cool.  This may make some recent
> work I've been doing on spatial and social network analyses of
> academic co-authorship easier (early code is here if you're
> interested:  http://refnet.r-forge.r-project.org/ ).  Thanks for
> providing this to the community!
>
> Sincerely,
> Forrest
>
> On Sun, Jun 23, 2013 at 10:20 PM, Thomas Adams <tea3rd@gmail.com> wrote:
> > Edzer,
> >
> > That's really pretty cool stuff; I think I can find some applications for
> > it!
> >
> > Cheers!
> > Tom
> >
> >
> > On Sun, Jun 23, 2013 at 5:57 PM, Edzer Pebesma <
> > edzer.pebesma@uni-muenster.de> wrote:
> >
> >> I did some simple things trying to combine sp and igraph objects to
> >> create spatial networks, and published this at:
> >>
> >> http://rpubs.com/edzer/spatialnetworks
> >>
> >> I'd be happy to share the markdown document with you; it seems to me
> >> that the rpubs don't allow you to simply download & run all the commands
> >> in the html.
> >>
> >> Anyway, comments & discussion welcome, as usual.
> >> --
> >> Edzer Pebesma
> >> Institute for Geoinformatics (ifgi), University of Münster
> >> Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
> >> 83 33081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de
> >>
> >> _______________________________________________
> >> R-sig-Geo mailing list
> >> R-sig-Geo@r-project.org
> >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >>
> >
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> >
> >
> > _______________________________________________
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> > R-sig-Geo@r-project.org
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >
>
>
>
> --
> Forrest R. Stevens
> Ph.D. Candidate, QSE3 IGERT Fellow
> Department of Geography
> Land Use and Environmental Change Institute
> University of Florida
> www.clas.ufl.edu/users/forrest
>
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