Re: longitude / latitude distance calculations

["Eric A. Wolf" <eric_a_wolf@xxxxxxxxxxx>]

There is a product available on the market by a company called WorksRight
Software that has software that does this called Z4LAT/LON.  I have not used
it but do use their Address Verification system to validate that addresses
and zip codes are entered correctly.  You may want to check it out at
www.worksright.com.

I am not in anyway affiliated with WorksRight - just a satisfied user of
their software at two customer sites.

Eric

----- Original Message ----- 
From: "Karen Brasier" <karen.brasier@xxxxxxxxx>
To: "'RPG programming on the AS400 / iSeries'" <rpg400-l@xxxxxxxxxxxx>
Sent: Wednesday, January 12, 2005 11:23 AM
Subject: longitude / latitude distance calculations


> Working on a project and need to know the distance in miles between two
> locations.  The information that I have in the file to use to do this is
the
> longitude and latitude.  I have seen the code in PC jargon, but have not
> been able to find anything about how to accomplish this in RPG.    Any
> suggestions would be appreciated... I am cutting/pasting the calc to
> accomplish this below...    as I look at this, I am lost! (or worse, lol)
> surely, there is an easier way, but in searching the archives, I found
> nothing on this...
>
>
>
> const pi = 3.14159265358979323846
>
> Function distance(lat1, lon1, lat2, lon2, unit)
>   Dim theta, dist
>   theta = lon1 - lon2
>   dist = sin(deg2rad(lat1)) * sin(deg2rad(lat2)) + cos(deg2rad(lat1)) *
> cos(deg2rad(lat2)) * cos(deg2rad(theta))
>   response.write "dist = " & dist & "<br>"
>   dist = acos(dist)
>   dist = rad2deg(dist)
>   response.write "dist = " & dist & "<br>"
>   distance = dist * 60 * 1.1515
>   Select Case ucase(unit)
>     Case "k"
>       distance = distance * 1.609344
>     Case "n"
>       distance = distance * 0.8684
>   End Select
> End Function
>
>
> '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
> ':::  this function get the arccos function using arctan function   :::
> '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
> Function acos(rad)
>   If abs(rad) <> 1 Then
>     acos = pi/2 - atn(rad / sqr(1 - rad * rad))
>   ElseIf rad = -1 Then
>     acos = pi
>   End If
> End function
>
>
> '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
> ':::  this function converts decimal degrees to radians             :::
> '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
> Function deg2rad(deg)
> deg2rad = cdbl(deg * pi / 180)
> End Function
>
> '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
> ':::  this function converts radians to decimal degrees             :::
> '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
> Function rad2deg(rad)
> rad2deg = cdbl(rad * 180 / pi)
> End Function
>
> msgbox(distance(32.9697, -96.80322, 29.46786, -98.53506, "m") & "
> miles<br>")
> msgbox(distance(32.9697, -96.80322, 29.46786, -98.53506, "k") & "
> kilometers<br>")
> msgbox(distance(32.9697, -96.80322, 29.46786, -98.53506, "n") & " nautical
> miles<br>")
>
> Karen Brasier
> I.T. Department - Software Analyst
> Standard Furniture Manufacturing Co.
> Bay Minette, Alabama 36507
> (251) 937-6741 ext 8848
> There are 10 kinds of people in the world, those that understand binary
and
> those that do not.
>
>
>
> -- 
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