Custom Function to Express Degree to/from as Fractions of Degrees

MORE INFORMATION

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements.

Converting Decimal Degrees to Degrees/Minutes/Seconds

The following Microsoft Visual Basic for Applications custom function accepts an angle formatted as a decimal value and convert it to a text value displayed in degrees, minutes, and seconds.

   Function Convert_Degree(Decimal_Deg) As Variant
       With Application
           'Set degree to Integer of Argument Passed
           Degrees = Int(Decimal_Deg)

           'Set minutes to 60 times the number to the right
           'of the decimal for the variable Decimal_Deg
           Minutes = (Decimal_Deg - Degrees) * 60

           'Set seconds to 60 times the number to the right of the
           'decimal for the variable Minute
           Seconds = Format(((Minutes - Int(Minutes)) * 60), "0")

           'Returns the Result of degree conversion
           '(for example, 10.46 = 10~ 27  ' 36")
           Convert_Degree = " " & Degrees & "~ " & Int(Minutes) & "' " _
               & Seconds + Chr(34)

       End With

   End Function
				

To use this function, create a conversion formula, as in the following example:

   =Convert_Degree(10.46)
				

This formula will return 10~ 27' 36" (that is, 10 degrees, 27 minutes, 36 seconds).

Converting Degrees/Minutes/Seconds to Decimal Degrees

The following Microsoft Visual Basic for Applications custom function accepts a text string of degrees, minutes and seconds formatted in the exact same format that the Convert_Degree function returns (for example, 10~ 27' 36") and converts it to an angle formatted as a decimal value. This is exactly the reverse of the Convert_Degree custom function.

WARNING: This custom function fails if the Degree_Deg argument does not follow the format of the following:

   <degrees>~ <minutes>' <seconds>"
				

as stated earlier.

Function Convert_Decimal(Degree_Deg As String) As Double

  ' Declare the variables to be double precision floating-point.
   Dim degrees As Double
   Dim minutes As Double
   Dim seconds As Double

   ' Set degree to value before "~" of Argument Passed.
   degrees = Val(Left(Degree_Deg, InStr(1, Degree_Deg, "~") - 1))

   ' Set minutes to the value between the "~" and the "'"
   ' of the text string for the variable Degree_Deg divided by
   ' 60. The Val function converts the text string to a number.
   minutes = Val(Mid(Degree_Deg, InStr(1, Degree_Deg, "~") + 2, _
             InStr(1, Degree_Deg, "'") - InStr(1, Degree_Deg, _
             "~") - 2)) / 60

    ' Set seconds to the number to the right of "'" that is
    ' converted to a value and then divided by 3600.
    seconds = Val(Mid(Degree_Deg, InStr(1, Degree_Deg, "'") + _
            2, Len(Degree_Deg) - InStr(1, Degree_Deg, "'") - 2)) _
            / 3600

   Convert_Decimal = degrees + minutes + seconds

End Function
				

To use this function, create a conversion formula, as in the following example:

   =Convert_Degree("10~ 27' 36""")
				

This formula will return 10.46 (that is, 10.46 degrees).

NOTE: You are required to type three quotation marks (""") at the end of argument of this formula to balance the quotation mark for the seconds and the quotation mark for the text string.