Highway Distance matrix

Hi,

I agree with Jeremy, but it seems that it's not very handy to use igraph to
compute the shortest path. I have developed a package "shp2graph"to
transform a road network data set from a SpatialLinesDataFrame. Based on
this, I have writen a guide to compute the shorest path in R, which is
available at the following link:

https://sourceforge.net/projects/shp2graph/files/Guide%20for%20computing%20shortest%20paths%20with%20given%20points%20and%20base%20network%20map.pdf/download

If any queries, please email me. Any comment or suggestion is welcome.

Binbin

On , Raphael Saldanha <saldanha.plangeo at gmail.com> wrote:

Thanks Jeremy! I will take a good look on this.

On Thu, Aug 4, 2011 at 11:36 AM, jeremy.raw at dot.gov> wrote:

There is certainly no need to go anywhere near ArcGIS for this type of

operation.

The simplest approach would be to look at one of the packages that does

shortest path evaluations on a network. On CRAN, the igraph package

lets you can do this pretty straightforwardly. Alternatively, the

travelr package on R-Forge (not actively maintained, but functional for

this purpose) is also available. Igraph is easier if you are

comfortable with basic graph theory (and translating to and from the

0-based indexing that the current version of igraph uses for node/vertex

numbering), whereas travelr may be easier if you are already comfortable

with transport modeling.

The basic steps are to convert your base map into a suitable

graph/network format (eg via what igraph calls an edgelist) and then

to use shortest.paths in igraph, or build.paths and skim.paths in

travelr, to compute the matrix of distances.

Igraph also has a help list where some of the set-up questions for this

type of problem have already been addressed:

https://lists.nongnu.org/mailman/listinfo/igraph-help

I hope that helps!

Jeremy Raw, PE

FHWA Office of Planning

jeremy.raw at dot.gov

(202) 366-0986

-----Original Message-----

From: r-sig-geo-bounces at r-project.org

[mailto:r-sig-geo-bounces at r-project.org] On Behalf Of Raphael Saldanha

Sent: Thursday, August 04, 2011 7:32 AM

To: r-sig-geo

Subject: [R-sig-Geo] Highway Distance matrix

Hi,

How can I compute a distance matrix of points (citys) based on a highway

base map?

Regards in advance,

Raphael Saldanha

saldanha.plangeo at gmail.com

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Atenciosamente,

Raphael Saldanha

saldanha.plangeo at gmail.com

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