I'm so confused. I'm finally getting around to needing to do a 'store
locator' thing.
I procured myself some zip/lat/long databases from various places. Then I
noticed that for the same zip code, I got different values in different
databases??!!!
So for a sanity check, I decided to look "online" and punch in some to see
what the "real" lat/long should be. Well, different sites give different
values, and not only are they "slightly" off, but sometimes they're
_positive_ or _negative_!? UGH!
http://www.zipinfo.com/cgi-local/zipsrch.exe?ll=ll&zip=98119&Go=Go
Seattle WA 98119 47.6388 122.3700
http://www.census.gov/cgi-bin/gazetteer?city=&state=&zip=98119
Location: 47.637917 N, 122.364272 W
http://www.csgnetwork.com/cgi-bin/zipcodes.cgi?Zipcode=98119
http://www.myzipdb.com/mzdb_demo.php
http://www.nearby.org.uk/coord.cgi?p=98119
City Seattle
State Abbreviation WA
State Washington
Latitude 47.638770
Longitude -122.366941
So I try the east coast:
http://www.zipinfo.com/cgi-local/zipsrch.exe?ll=ll&zip=14526&Go=Go
Penfield NY 14526 43.1532 77.4485
http://www.census.gov/cgi-bin/gazetteer?city=&state=&zip=14526
Location: 43.139638 N, 77.456043 W
http://www.csgnetwork.com/cgi-bin/zipcodes.cgi?Zipcode=14526
http://www.nearby.org.uk/coord.cgi?p=14526&f=full
City Penfield
State Abbreviation NY
State New York
Latitude 43.145342
Longitude -77.458499
Please help me to understand WTF is going on?
Which lat/long do I need?
How does the negatives effect the magic formulas to calculate distances?
(I'm no trig wiz).
I assume that the more precise the numbers, the better the results will be.
To what decimal point should I be concerned with?
