On 9/6/07, Ted Harding <[EMAIL PROTECTED]> 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: [EMAIL PROTECTED] > > > > 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.
I think it's perfectly well-posed, but you'll need to use some resources outside of R. The term for converting street addresses to lat/long values is called geocoding, and wikipedia has a good introduction: http://en.wikipedia.org/wiki/Geocoding. There are a couple of free geocoding web services for US addresses: e.g. http://developer.yahoo.com/maps/rest/V1/geocode.html or http://geocoder.us/. For non-US addresses you'll have to google around (e.g. international geocoding), and depending on the country and level of detail you require, you may have to pay. Once you've got lat and longs, computing grand circle distance is easy. Computing driving distances is harder, but may be possible with (e.g.) the google maps API - http://www.google.com/apis/maps/documentation/index.html#Driving_Directions. Googling for driving directions api suggests some other possibilities. Hadley ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
