[R] computing distance in miles or km between 2 street addre

[Nordlund, Dan (DSHS/RDA)]

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Duncan Murdoch
> Sent: Thursday, September 06, 2007 4:54 PM
> To: ted.harding at manchester.ac.uk
> Cc: r-help at stat.math.ethz.ch; Philip James Smith
> Subject: Re: [R] computing distance in miles or km between 2 
> street addre
> 
> On 06/09/2007 6:17 PM, (Ted Harding) wrote:
> > On 06-Sep-07 18:42:32, Philip James Smith wrote:
> >> Hi R-ers:
> >>
> >> I need to compute the distance between 2 street addresses in
> >> either km or miles. I do not care if the distance is a "shortest
> >> driving route" or if it is "as the crow flies."
> >>
> >> Does anybody know how to do this? Can it be done in R? I have
> >> thousands of addresses, so I think that Mapquest is out of the
> >> question!
> >>
> >> Please rely to: philipsmith at alumni.albany.edu
> >>
> >> Thank you!
> >> Phil Smith
> > 
> > That's a somewhat ill-posed question! You will for a start
> > need a database of some kind, either of geographical locations
> > (coordinates) of street addresses, or of the metric of the
> > road network with capability to identify the street addresses
> > in the database.
> > 
> > If it's just "as the crow flies", then it can be straightforwardly
> > computed in R, either by Pythogoras (when they are not too far
> > apart) or using a function which takes account of the shape of
> > the Earth,
> > 
> > There are many R packages which have to do with mapping data.
> > Search for "map" through the list of R packages at
> > 
> > http://finzi.psych.upenn.edu/R/library/maptools/html/00Index.html
> > 
> > -- maptools in particular. Also look at (for instance) aspace.
> > 
> > For "shortest driving route" then you need to find the shortest
> > distance through a network. You may find some hints in the
> > package optim -- but there must be some R experts out there
> > on this sort of thing!
> > 
> > However, the primary need is for the database which gives
> > the distance information in one form or another. What were
> > you proposing to use for this? As far as I know, R has no
> > database relevant to street addresses!
> 
> But if the addresses are in the US and include zip codes, a 
> database is 
> available online for free, here:
> 
> http://www.aggdata.com/files/zip_codes.zip
> 
> This includes latitude and longitude.  Zip codes cover a fairly large 
> area so this won't give very accurate information, but it's 
> easy to get.
> 
> Duncan Murdoch
> 

There are a number of free address geocoding sites on the web, some of which even support moderate amounts of batch geocoding for non-commercial purposes.  The following URL is just one of the available sites turned up by Googling "address geocoding free".  Of course, there are also a number of commercial sites.

http://www.batchgeocode.com/

Hope this is helpful,

Dan

Daniel J. Nordlund
Research and Data Analysis
Washington State Department of Social and Health Services
Olympia, WA  98504-5204