[RESOLVED] How to Convert Decimal Degrees (DD) to Degrees-Minutes-Seconds (DMS)

[matrik02]

How to convert decimal degrees (example: 42.36824) to 42 deg., 22 min., 06 sec. in Visual Basic

Manual calculation

(1) The Degrees are simply the numbers to the left of the decimal (using 42.36824 as in the example above, the degrees would be 42)
(2) To determine the Minutes, multiply the number to the right of the decimal point by 60 (example: .36824 x 60 = 22.0944)
(3) The Minutes are the numbers to the left of the decimal point (in this example, 22)
(4) To determine the Seconds, multiply the number to the right of the decimal point by 60 (example: .0944 x 60 = 5.664)
(5) The Seconds are the numbers to the left of the decimal point, rounded up (in this example, 06)

[westconn1]

in steps, same as manual calculation, just make sure to force rounding as appropriate

if you get stuck post the problem code and someone will help

[Spoo]

Matrik

As LaVolpe mentioned, you very nicely described the process
in your "manual calculation" list of steps.

Maybe something along these lines will give you a booster start ...

Dim nDecDeg as Double
Dim nDeg as Integer
Dim nMin as Integer
Dim nSec as Integer
Dim txtDeg as String
'
nDecDeg = 42.36824
' 1. deg
nDeg = Int(nDecDeg)      ' 42
v1 = nDecDeg - nDeg      ' .36824
v2 = v1 * 60             ' 22.0944
' 2. min
nMin = Int(v2)           ' 22
v3 = v2 - nMin           ' .0944
v4 = v3 * 60             ' 5.664
' 3. sec
nSec = Int(v4)           ' 5
v5 = v4 - nSec           ' .664
' 4. rounding
nSec = nSec + IIf(v5 >= 0.5, 1, 0)   ' 5 + 1 = 6 ... rounded up
' 5. create string with leading 0's if number is < 10
txtDeg = Format(nDeg, "00") + " deg., " _
       & Format(nMin, "00") + " min., " _
       & Format(nSec, "00") + " sec. "

Spoo

[opus]

Hey Spoo, you forgot the execption for a round up when nSec was already 59, which would lead to a new Minute which could lead to a new hour!

[matrik02]

hi Opus, what the problem with the code, I test it look fine to me. What your suggestion?

[matrik02]

I test the code, something problem, it show 42 deg, 59 min and 60 sec,

nDecDeg = 42.9999
' 1. deg
nDeg = Int(nDecDeg)      ' 42
v1 = nDecDeg - nDeg      ' .36824
v2 = v1 * 60             ' 22.0944
' 2. min
nMin = Int(v2)           ' 22
v3 = v2 - nMin           ' .0944
v4 = v3 * 60             ' 5.664
' 3. sec
nSec = Int(v4)           ' 5
v5 = v4 - nSec           ' .664
' 4. rounding
nSec = nSec + IIf(v5 >= 0.5, 1, 0)   ' 5 + 1 = 6 ... rounded up
' 5. create string with leading 0's if number is < 10
txtDeg = Format(nDeg, "00") + " deg., " _
       & Format(nMin, "00") + " min., " _
       & Format(nSec, "00") + " sec. "
MsgBox txtDeg

[opus]

That what I was pointing at, at the end you need to check wether you have such rollups (i.e. when Seconds are 60 set seconds to 0 and Minute +1, then do the same for minutes and then for houres as well).

[opus]

If you start the wholev from the back it should be easier.
You could try this one:

nDecDeg = 42.9999
nDecDeg = Round(nDecDeg * 3600)
nDeg = Int(nDecDeg / 3600)
nMin = Int((nDecDeg - nDeg * 3600) / 60)
nsec = Int(nDecDeg - nDeg * 3600 - nMin * 60)
txtDeg = Format(nDeg, "00") + " deg., " _
       & Format(nMin, "00") + " min., " _
       & Format(nsec, "00") + " sec. "
MsgBox txtDeg

[dilettante]

This seems to work for positive and negative values:

Option Explicit

Private Function FmtDegAsDegMinSec(ByVal Degrees As Double) As String
    Dim DegPart As Double
    
    Degrees = Round(Degrees * 3600#) / 3600#
    DegPart = Fix(Degrees)
    FmtDegAsDegMinSec = _
        CStr(DegPart) & " deg., " _
      & Format$((Degrees - DegPart) / 24#, "NN"" min., ""SS"" sec.""")
End Function

Private Sub Command1_Click()
    MsgBox FmtDegAsDegMinSec(CDbl(Text1.Text))
End Sub

[opus]

Damm it, I missed the negative values:

ndecdeg = -42.999
ndecdeg = Round(ndecdeg * 3600)
nDeg = Fix(ndecdeg / 3600)
ndecdeg = Abs(ndecdeg - nDeg * 3600)
nMin = Fix(ndecdeg / 60)
nsec = Fix(ndecdeg - nMin * 60)
txtDeg = Format(nDeg, "00") + " deg., " _
       & Format(nMin, "00") + " min., " _
       & Format(nsec, "00") + " sec. "
MsgBox txtDeg

Should do it.

[VBClassicRocks]

Another $.02

Function FormatDMS(ByVal Degs As Double) As String
 Dim Sign As Long
 Sign = Sgn(Degs)
 Degs = Int(Abs(Degs) * 3600 + 0.5) / 3600 '-- rounding to second
 FormatDMS = Sign * (Int(Degs)) Mod 360 & Format(Degs / 24, "°nn'ss\""")
End Function

[Spoo]

Matrik

Regarding ...

I test the code, something problem, it show 42 deg, 59 min and 60 sec,

... I should have added to my OP that it was an
admittedly "brute force" approach, and that I had not
tested it !!.

Have you been able to resolve the problem?
If not, do any of the other suggestions do the trick?

Spoo