eBlush_Hector — Thu, 02 Dec 2004 15:33:59 +0000

In perl:

sub great_circle_distance {
my $lon_1=shift;
my $lat_1=shift;
my $lon_2=shift;
my $lat_2=shift;

# Convert all the degrees to radians
$lat_1 = &deg_to_rad($lat_1);
$lon_1 = &deg_to_rad($lon_1);
$lat_2 = &deg_to_rad($lat_2);
$lon_2 = &deg_to_rad($lon_2);

# Find the deltas
my $delta_lat = $lat_2 - $lat_1;
my $delta_lon = $lon_2 - $lon_1;

# Find the Great Circle distance
my $temp = sin($delta_lat/2.0)**2 + cos($lat_1) * cos($lat_2) * sin($delta_lon/2.0)**2;

# EARTH_RADIUS = 3956

my $distance = 3956 * 2 * atan2(sqrt($temp),sqrt(1-$temp));

return($distance);
}

sub deg_to_rad {
my $deg_2 = shift;
my $radians = 0.0;
my $pi = atan2(1,1) * 4;
$radians = $deg_2 * $pi/180.0;
return($radians);
}

forwardtrends — Wed, 27 Oct 2004 03:34:13 +0000

I did this about a year ago - let me look for it but I know I found a free one somewhere in .CSV format and it imported fine through Enterprise Manger (MSSQL). I've also got asp code that calculates radius in miles given you have the longitude and latitude coords, it uses pi to compensate for the natural curvature of earth. Hopefully I can find it and I'll post it up here asap.

Greg K — Fri, 08 Oct 2004 19:02:38 +0000

I just recieved an e-mail today from the company that we purchased our data from. Here is their link: http://www.zipinfo.com/products/products.htm

-Greg

Politicalgatewa — Fri, 08 Oct 2004 10:57:13 +0000

get teh 29 dollar one, comes in excel format or cvs....zip + 5..

works great

http://www.zipinfo.com/products/z5/z5.htm

OtterBob — Fri, 24 Sep 2004 13:14:24 +0000

I'm not aware of any, but it should be pretty trivial to convert the format if necessary. For instance, the Zipwise products are in CSV format. I would imagine most database programs should be able to import a CSV file, or a tab-delimited file which would be easily created from the CSV.

Waterlogged — Thu, 23 Sep 2004 22:37:38 +0000

Thanks guys I will look into those any SQL databases you guys might know about?

Greg K — Thu, 23 Sep 2004 19:43:15 +0000

You can try something like:

http://www.zipwise.com/zip-code-downloads.php

I was trying to find the link to the one we bought, I remember I labeled the CD "ProZip", the one we bought had all kinds of info. We got the one with longitude and latitude for possible future "search near" features.

-Greg

OtterBob — Thu, 23 Sep 2004 10:22:18 +0000

Give http://www.usps.com a try. They've got a CD you might be able to use.