Geocoding with Google Maps and Igor

// Function Uses Google maps to return latitude and longitude of an address
// Requires: easyHttp XOP
// Geoff Dutton March 5, 2009
Function GeocodeWithGoogle( )

    Make /o/n=6 lat = 0, long = 0
    Make /o/n=6 /T city, state
   
    city = {"Denver", "Los Angels", "Boise", "Pensacola", "Dallas", "1600 Pennsylvania Ave NW, Washington"}
    state = {"Colorado", "California", "Idaho", "Florida", "Texas", "DC"}
   
    String Win = "Geocode"
    Dowindow /K $Win
    Edit city, state, lat, long
    Dowindow /C $Win
    DoUpdate

    String url, GmapOutput
    Variable i
   
    for (i=0; i<numpnts(lat); i+=1 )
       
        // only Geocode if lat = 0
        if ( lat[i] == 0 )
            // build a URL for Google maps
            Sprintf url, "http://maps.google.com/maps/geo?q=%s,%s&output=csv&quot;, city[i], state[i]
           
            // replace spaces in URL with unicode
            url = ReplaceString(" ", url, "%20")
           
            // use easyHttp to contact Google maps, Google maps returns lat, long encoded text
            easyHttp url
            GmapOutput = S_getHttp

            // create a list from returned Google text
            GmapOutput = ReplaceString(",", GmapOutput, ";")
           
            // Google returns 200 if address was found
            if ( str2num(StringFromList( 0, GmapOutput)) == 200 )
                lat[i] = str2num(StringFromList(2, GmapOutput))
                long[i] = str2num(StringFromList(3, GmapOutput))
                Printf  "%s, %s is located at %.5f, %.5f\r", city[i], state[i], lat[i], long[i]
            else
                Print "ERR: " + city[1] + ", " + state[2]
            endif
           
            // slow down a little (for googles' servers)
            DoUpdate
            Sleep /T 1/10
        endif

    endfor
   
end