[R-sig-Geo] Highway Distance matrix

[Roger Bivand]

On Thu, 4 Aug 2011, lubinbin220 at gmail.com wrote:

> 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.

And note that it will be presented at useR! in Coventry (UK) on 
Wednesday 17 August, 16.00 - 17.05, B3.03, with other spatial papers (see 
also 11.15 - 12.35, B3.02 same day). All welcome!

Roger

>
> 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
>
>>>
>
>>> [[alternative HTML version deleted]]
>
>>>
>
>>> _______________________________________________
>
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>
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>
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>
>>>
>
>
>
>
>
>
>
>> --
>
>> Atenciosamente,
>
>
>
>> Raphael Saldanha
>
>> saldanha.plangeo at gmail.com
>
>
>
>> [[alternative HTML version deleted]]
>
>
>
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>
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>
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>
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>
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>
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-- 
Roger Bivand
Department of Economics, NHH Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no