Well, latitude to distance is fairly simple -- it's just the circumference
of the earth divided by 360, which equals about 69 miles. The longitude
conversion will vary with latitude. At the equator (lat=0 degrees), one
degree longitude equals one degree latitude. The value drops as move away
from the equator of course. I think that at latitudes of 30, 40, and 50
degrees it's about 60, 53, and 44 miles respectively. You can use some trig
if you need to get more precise.
Michael Blasnik
[email protected]
----- Original Message -----
From: "Glen Waddell" <[email protected]>
To: "Statalist" <[email protected]>
Sent: Monday, September 29, 2003 2:30 PM
Subject: st: Latitude/longitude in spatwmat
>
> I currently have latitude and longitude coordinates in a dataset but
> need to have them projected onto an {x,y} plane in order to take
> advantage of the 'spatwmat' command. Do you know if there is a
> conversion equation, or at least a legitimate approximation for small
> areas?
>
> Glen
>
> ____________________________
> Glen R. Waddell
> Department of Economics
> University of Oregon
> Eugene, OR 97403-1285
> phone: (541) 346-1259
> fax: (541) 346-1243
> www.uoregon.edu/~waddell/
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