Does anybody have any experience working with latitudes, longitudes,
distances and timing? If you have, I'm looking for a good way to enter
lat/long as
hddd' mm.mmm' and as xxdmm'mm''.mm (where in the last case the d is the
degrees sign, '=minutes and '' =seconds).
Ofcourse I can simply create a text-field for all of this and then calculate
whatever I need, but there might be a bette way to do this.

I already have built a function that calculates the distance between two
lat, long points. So no problem there, but I'm very curious what solutions
there might be.

--
Keep Well,
Ursus

ursus.kirk <secret (AT) nowhere (DOT) com> wrote:

I found a very old example at

http://www.dwdataconcepts.com/dl/tw/Distance.zip

You can convert to any later version of FM since it's in .fp3 format.

He just enters the data as "117.7609"

Lynn Allen
--
Allen & Allen Semiotics www.semiotics.com
FSA Associate Filemaker Design & Consulting

In article <1gzuece.bta1isclajssN%lynn (AT) NOT-semiotics (DOT) com>,
lynn (AT) NOT-semiotics (DOT) com (Lynn allen) wrote:

This does not address Ursus' question, which is how to enter the Lat &
Long in the format degrees:minutes

My first suggestion is to use two fields for each coordinate, one for
degrees and another for minutes and tenths, then a calculation field
that combines them to yield the coordinate in degree decimal form, thus:

Number field: Lat1Degree (number in form ddd)
Number field: Lat1Minute (number in form mm.mmm)

Calculation field: Lat1 = Lat1Degree + Lat1Minute/60

and so on.

An alternative approach might be to use a time field, and enter the lat
or Lon in the format

ddd:mm:ss

where ddd is whole degrees, treated as hours in the time field, mm is
minutes of arc, and ss is seconds of arc.

For example, Lat1dms would be a time field, with data entered in the
form ddd:mm:ss

You would then calculate degrees of the coordinate as a decimal number
thus:

Lat1 = Hour(Lat1dms) + Minute (Lat1dms)/60 + Second (Lat1dms)/3600


However, when I tried to enter minutes of arc with a decimal fraction,
instead of using seconds of arc, the calculation does not work, so I do
not think you can use this method for minutes and tenths (or
hundredths).

However, the method I suggested first, with separate number fields for
degrees and minutes, does work with minutes in decimal fraction form.

Bill Collins

--
For email, remove invalid.