
 
Phil,
 
If you have only a list of addresses and nothing else - i have to recognize i am "lost". But if you have more info you can use a GIS software and it will calculate your distance automatically for all your addresses. To have your distance in miles or Km you need to have a projection in your data which will establish your units.
 
The very basic principle is that for each address you have a set of coordinates, x, y and you actually use these to calculate distances. If your file is for exaple a point shape file (standard for ESRI ArcGIS products) you can very simply perform this task using either "shortest driving route" or "as the crow flies" - again depending on what other info you have in the file. A "shape file" is actually a group of files with with data attributes, projection info and so on - so even if you don't see xy coordinates, they actually are imbeded in the file.
 
I suspect Mapquest or any other mapping web product has a database with all those addresses with xy coordinates. The user needs to know only the address and behind doors there is an sql process which selects particular addresses together with all the other attributes attached to it and calculate distances because it "knows" coordinates, a network of roads and so on.
 
I am not sure this helps but at least maybe gives you some ideas where to look next.
Monica
 

Message: 53Date: Thu, 06 Sep 2007 14:42:32 -0400From: Philip James Smith <philipsmith@alumni.albany.edu>Subject: [R] computing distance in miles or km between 2 streetaddressesTo: r-help@stat.math.ethz.chMessage-ID: <46E04A18.7040909@alumni.albany.edu>Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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@alumni.albany.edu Thank you!Phil Smith  
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