On 07/11/2014 11:13 AM, wrote:
Hello all,

How can I convert a decimal fraction (for example 10.5) to binary form and vice versa (i.e., if I have a binary form such as 10010.011 back to decimal form)?

The DEC2BIN function in Excel works for Whole numbers and not fractions.

Please suggest!!

Here's a solution posted by Rick Rothstein some years ago...

Function DecToBin(ByVal DecimalIn As Variant, Optional NumberOfBits As
Variant) As String
' The DecimalIn argument is limited to 79228162514264337593543950266
' (approximately 96-bits) - large numerical values must be entered
' as a String value to prevent conversion to scientific notation.

DecToBin = "": DecimalIn = CDec(DecimalIn)
Do While DecimalIn < 0
DecToBin = Trim$(Str$(DecimalIn - 2 * Int(DecimalIn / 2))) & DecToBin
DecimalIn = Int(DecimalIn / 2)
Loop
If Not IsMissing(NumberOfBits) Then
If Len(DecToBin) NumberOfBits Then
DecToBin = "Error - Number too large for bit size"
Else
DecToBin = Right$(String$(NumberOfBits, "0") & DecToBin,
NumberOfBits)
End If
End If
End Function

Function BinToDec(BinaryString As String) As Variant
' BinaryString argument can be a maximum of 96 digits (either 0's or 1's)

Dim x As Integer
Const TwoToThe48 As Variant = 281474976710656#
For x = 0 To Len(BinaryString) - 1
If x 48 Then
BinToDec = CDec(BinToDec) + Val(Mid(BinaryString,
Len(BinaryString) - x, 1)) * TwoToThe48 * CDec(2 ^ (x - 48))
Else
BinToDec = CDec(BinToDec) + Val(Mid(BinaryString,
Len(BinaryString) - x, 1)) * CDec(2 ^ x)
End If
Next
If Len(BinToDec) 10 Then BinToDec = CStr(BinToDec)
End Function


--
-
Garry

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