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Mike Dorl wrote-

>Is there anyway to use excel with dd mm ss data?
>
>I've been using the following macros to convert back and forth.  To add
>them to a sheet,use TOOLS - MACRO - VISUAL BASIC EDITOR.
>Then after visual basic stars, do INSERT MODULE and paste them into the
>resulting window.
>
>Mike
>
>
>Function DMStoDEC(s As String) As Double
>
>Dim parts() As String
>
>Dim Degrees As Integer
>Dim Minutes As Integer
>Dim Seconds As Integer
>Dim sign    As Integer
>
>parts = Split(s, , , vbBinaryCompare)
>
>Degrees = parts(0)
>If Degrees < 0 Then
>  sign = -1
>  Degrees = -Degrees
>Else
>  sign = 1
>End If
>
>Minutes = parts(1)
>Seconds = parts(2)
>
>DMStoDEC = sign * (Degrees + Minutes / 60# + Seconds / 3600#)
>
>End Function
>
>
>Function DECtoDMS(A As Double) As String
>
>Dim Degrees As Integer
>Dim Minutes As Integer
>Dim Seconds As Double
>
>Degrees = Int(A)
>A = 60 * (A - Degrees)
>Minutes = Int(A)
>Seconds = 60# * (A - Minutes)
>Seconds = Round(Seconds, 3)
>Seconds = Int(Seconds * 1000#)
>Seconds = Seconds / 1000#
>
>DECtoDMS = Degrees & " " & Minutes & " " & Seconds
>
>End Function

=======================

Comment from George-

Cliff Sojourner responded to my comments about a possible weakness in Chuck
Taylor's angle conversion-

"that's the first thing I checked in the VB code posted earlier; that one
got it right too." I presume Cliff is referring to Mike Dorl's routine,
quoted above

But does Mike's routine get it right in all cases? I think I can see where
it might break down.

How will it cope with an angle that's -0deg 30'?

The test for negative angle is made only on the degrees, not minutes or seconds.

So, in that example, it has to make the test as to whether -0 is less than zero.

I am unfamiliar with the Visual Basic that's in use here (my pocket
calculator uses a much more rudimentary form of Bsic) but I suspect most
computing programs will answer that it isn't less than zero, in which case
Mike Dorl's program will fall down, treating an angle of -0deg 30' exactly
the same as +0deg 30', to give +0.5 deg where it should have been -0.5 deg.


A safer test for negativity might be to search for a "minus" character,
somewhere in the string.

Mike may have checked this aspect already, but if not he would be wise to
try out his routine on an angle that's negative, and less than 1 degree.

What's more, I have a strong suspicion that Mike's converse routine for
degrees-to-dms will go wrong for any negative angle: I certainly recommend
that he checks it out. Try converting -0.25deg, wich ought to give a result
of -15'; I suspect that it will give -45'.

I have become aware of such possible waywardness in angle conversion only
by experience; in making such mistakes myself, then (the hard part)
uncovering them, then (the easy part) correcting them.

George.

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