Converting to Roman numerals

[seoptimizer2001]

Is there any function in VB that converts numbers to Roman Numerals? I know there is one in Excel. Please help.

[Gerco]

AFAIK, no, you'll have to write one yourself. (or find someone to do it for you)

[Matthew Gates]

Attached is a control that'll do the job for you.

[beachbum]

Are u serious!! Does Excel really have that?? No wonder it is called bloatware. I am sure converting any number to Roman Numerals would be dead easy in code, even easier than converting numbers to words for cheques/checks.

[Nucleus]

How do you count in Roman Numerals?

I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV,

20?
30?
40?
50?
60?
70?
80?
90?
100?
1,000?
1,000,000?
1,000,000,000?

[Nucleus]

Ok I found a definition of roman numerals here:
http://www.cod.edu/people/faculty/lawrence/romans00.htm

On the basis of this try this function:

Public Function NumToRN(ByVal Num As Variant) As String
 ' Nucleus
 ' Turn an integer into roman numerals
 Dim Compare@, Div@, b As Boolean
 Num = CCur(FormatNumber(Num, 0)) ' Round to nearest integer and convert to currency
 
 Compare = 1000
 
 Do While Num
    
    Div = Num / Compare
    
    If Div >= 1 Then
        
        NumToRN = NumToRN & String(Int(Div), RomanNumerals(Compare))
        Num = Num - Int(Div) * Compare
        
    Else
    
        If b And Div >= 0.8 And Div < 1 Then
            NumToRN = NumToRN & RomanNumerals(0.8 * Compare)
            Num = Num - 0.8 * Compare
        
        ElseIf Not b And Div >= 0.9 And Div < 1 Then
            NumToRN = NumToRN & RomanNumerals(0.9 * Compare)
            Num = Num - 0.9 * Compare
            
        End If
        
        If Not b Then Compare = Compare / 2 Else Compare = Compare / 5
        b = Not b
        
    End If
    
 Loop
 
End Function
 
 
Private Function RomanNumerals(ByVal Num As Variant) As String
 Num = FormatNumber(Num, 0)
 Select Case Num
    Case 1
        RomanNumerals = "I"
    Case 4
        RomanNumerals = "IV"
    Case 5
        RomanNumerals = "V"
    Case 9
        RomanNumerals = "IX"
    Case 10
        RomanNumerals = "X"
    Case 40
        RomanNumerals = "XL"
    Case 50
        RomanNumerals = "L"
    Case 90
        RomanNumerals = "XC"
    Case 100
        RomanNumerals = "C"
    Case 400
        RomanNumerals = "CD"
    Case 500
        RomanNumerals = "D"
    Case 900
        RomanNumerals = "CM"
    Case 1000
        RomanNumerals = "M"
 End Select
End Function

Usage:

Private Sub Command1_Click()
 MsgBox NumToRN(1999)
End Sub

Use with caution as has only just been thrown together. Any bug please post.

I could if you know how to draw a line over letters like V then I can ammend the function to include the shorthand for larger numbers such as 900,000 which is CM with line over it rather than a string of 900 Ms.

Also does the function need to handle negative numbers?

[seoptimizer2001]

Thanks all for the replies. I ended up writing my own function that works. I was hoping to find something else, but didn't see your control Matt until I was already done. BeachBum, yes Excel really has a Roman function for converting decimal to roman numerals, it should be in VB then I would of thought, but no. Anyways thanks for the help.

[wossname]

I don't know why all these historians rattle on about how clever the Romans were, oh wow they invented underwater concrete, whoopy-doo. They could do that, but a decent numerical notation was apparently above them!

I was told by a reliable source that there are at least 3 different ways to write the number 127454 in Roman numerals (I may have remembered that num wrong though). In any other sensible number system, there is only ever 1 way to write a number!

Ooh, Mr Glatiator, what a big gladivs you have, hey pvt that down! Arggggghhhhhh!!

[Nucleus]

Originally posted by seoptimizer2001
Thanks all for the replies. I ended up writing my own function that works. I was hoping to find something else, but didn't see your control Matt until I was already done. BeachBum, yes Excel really has a Roman function for converting decimal to roman numerals, it should be in VB then I would of thought, but no. Anyways thanks for the help.

Can you post or send me your function seoptimizer?

wossname,

I was told by a reliable source that there are at least 3 different ways to write the number 127454 in Roman numerals (I may have remembered that num wrong though). In any other sensible number system, there is only ever 1 way to write a number!

How does having multiple ways of writing a number reduce it's sensibility? Perhaps it provides more flexibility?

[Jim Brown]

Originally posted by Nucleus


How does having multiple ways of writing a number reduce it's sensibility? Perhaps it provides more flexibility?

Well I suppose in a superficial way one could say it's more flexible, but why does it need to be? My route to work is flexible, because I can make decisions based on traffic and so on: there's no earthly reason to want to write a number in more than one way. Indeed, it might make it worse, because I might write the number in one of the less obvious ways- or should I say less common- and then most people would have to puzzle over what I'm getting at and get it wrong.

Somewhere else in this thread it was asked about negative numbers. If I remember correctly, RNs had no concept of Zero, and so it's probably unlikely that they would have -ves, I think.

Last year my son, in 1st grade, got bored with his arithmetic homework and did a whole page of sums using RNs instead. He concluded it was quite a pain, because there's no 0 and no way that he could see, to carry.

[Nucleus]

Adding subtracting are difficult, multiplication and division almost impossible with RN. To me this is a bigger problem rather than having more than one way to write a number.