google maps api 3 - Formula to match Street Address based on slightly different Lat/Lng values -

is there proven formula match different lat/lng values street address without submitting both of them geocoding service (since we've done , don't want make second api call).

eg. following coordinates same street address (55 church street zip code 07505), 1 set points building , other street.

lat : 40.9170109 long: -74.1702248

lat: 40.9171216 long: -74.1704997

so there commonly used formula can use, perhaps effect of , match first 4 decimal places or subtract 2 lat values , 2 long values , if difference less x , same street address. these ideas based on definitions of lat/long, looking proven, perhaps industry standard formula if exists.

for measuring distances in close proximity pythagoras or variation of adequate. may have heard of haversine formula overkill close proximities.

for locations near equator pythagoras adequate move away equator becomes less accurate due convergence of meridians(longitude) approach poles. compensated in equirectangular() function

as tag google maps following javascript functions can used. note d in meters.

for example pyth() gives 33meters , equirectangular() 26meters. completeness haversine() give 26meters.

function torad(value) { /** converts numeric degrees radians */ return value * math.pi / 180; }  function pyth(lat1,lat2,lng1,lng2){     var x = torad(lng2-lng1) ;     var y = torad(lat2-lat1);     var r = 6371000; // gives d in meters     var d = math.sqrt(x*x + y*y)* r;     return d;  }   function equirectangular(lat1,lat2,lng1,lng2){     var x = torad(lng2-lng1) * math.cos(torad(lat1+lat2)/2);     var y = torad(lat2-lat1);     var r = 6371000; // gives d in meters     var d = math.sqrt(x*x + y*y)* r;     return d; }