Convert VB Double to Pascal Real

**One Handed Man** · Nov 20 '05, 07:54 AM

Re: Convert VB Double to Pascal Real

I probably have not understood you correctly, but can you not simply convert
the double to a string an then truncate the string to the correct length?

As far as I am aware, a real number is simply a number which is not
imaginary, so I dont know how this differs in a Pascal Real number. Your
function seems to convert a string into a double but goes a long way around.
BTW, I actually tried to convert "1.2345" and it returned 0.0

I'm sure Im missing something here, can you illuminate ?

Regards - OHM

David Scemama wrote:[color=blue]
> Hi,
>
> I'm writing a program using VB.NET that needs to communicate with a
> DOS Pascal program than cannot be modified. The communication channel
> is through some file databases, and I have a huge problem writing VB
> Double values to the file so as the Pascal program can read them as
> Pascal Real values.
>
> I've managed to find the algorithm to read the Pascal Real format and
> convert it to a VB Double, but I cannot figure out the opposite
> algorithm.
>
> Can someone help me reverse my algorithm and develop the function
> "DoubleToRe al (ByVal Data As Double) As String"
>
> Here is the conversion from real to double:
>
> Public Function RealToDouble(By Val Data As String) As Double
> Dim dMantissa As Double
> Dim i As Integer
> Dim j As Long
> Dim k As Long
>
> If Len(Data) <> 6 Then
> 'Err.Raise
> 'exception
> Exit Function
> End If
>
> 'accumulate the mantissa
> dMantissa = 1
> For i = 6 To 2 Step -1
> For j = CType(IIf(i = 6, 6, 7), Long) To 0 Step -1
> k = k + 1
> If (Asc(Mid$(Data, i, 1)) And CType(2 ^ j, Long)) <>
> 0 Then dMantissa = dMantissa + 2 ^ -k
> End If
> Next j
> Next i
>
> 'finally, assemble all the pieces into a number
> If (Asc(Mid$(Data, 6, 1)) And &H80) = &H80 Then
> RealToDouble = -dMantissa * 2 ^ (Asc(Mid$(Data, 1, 1)) -
> 129) Else
> RealToDouble = dMantissa * 2 ^ (Asc(Mid$(Data, 1, 1)) -
> 129) End If
>
> Try
> Return ([Decimal].Round(CDec(Rea lToDouble), 2))
> Catch ex As Exception
> 'MsgBox("RealTo Double, Conversion error: " & Data & "; " &
> RealToDouble.To String, MsgBoxStyle.Cri tical)
> Return 0
> End Try
>
> End Function
>
> Thanks for your help
> David[/color]

**Cor** · Nov 20 '05, 07:54 AM

OT: Re: Convert VB Double to Pascal Real

Hi OHM

Can you take a look at that answer from cc I have sended in and give some
comments.

All is there just paste it on a new form and run.

Or I don't understand it (and no user will understand it) or it is a real
big bug.

Cor

**One Handed Man** · Nov 20 '05, 07:54 AM

Re: Re: Convert VB Double to Pascal Real

I think my reader must be out of sync here. I dont see this reply. I have
noticed this with quite a few posts lately. Can you repost under this one
please.

Thanks - OHM

Cor wrote:[color=blue]
> Hi OHM
>
> Can you take a look at that answer from cc I have sended in and give
> some comments.
>
> All is there just paste it on a new form and run.
>
> Or I don't understand it (and no user will understand it) or it is a
> real big bug.
>
> Cor[/color]

**Cor** · Nov 20 '05, 07:54 AM

OT: Repost posible Bug

Hi OHM this was a question from cc
[color=blue]
> how do I make keyboard & mouse temporary not response to desktop[/color]

I did want to answer with simple" me.enabled = false", but did not trust it
because this answer seems to simple to me. So I did test it, and I find
this strange and do not understand it.

Who will test it also and tell me if this is normal behaviour or a bug?
The problem is that when you pusth the button when enabled is false, it
keeps responding to the events, so you have to push several times on the not
locked button.

Framework 1.1

Cor

\\\
' needs one button and one label on a form
Private Sub Button1_Click(B yVal sender As System.Object, _
ByVal e As System.EventArg s) Handles Button1.Click
Static i As Integer
Me.Button1.Text = "locked"
Dim ctr As Control
' Me.Enabled = false did not work so
'I did try this but does not work either
For Each ctr In Me.Controls
ctr.Enabled = False
Next
Me.Refresh()
Dim y As Integer
For y = 1 To 20
Threading.Threa d.Sleep(50)
i = i + 50
Me.Label1.Text = i.ToString
Me.Refresh()
Next
For Each ctr In Me.Controls
ctr.Enabled = True
Next
Me.Button1.Text = "Unlocked"
End Sub
///

**One Handed Man** · Nov 20 '05, 07:54 AM

Re: Repost posible Bug

But this post is about Mouse and keyboard, the current thread we are in is
regarding Double/Pascal Real number conversions?

Whats happening, am I going mad ?

Regards OHM

Cor wrote:[color=blue]
> Hi OHM this was a question from cc
>[color=green]
>> how do I make keyboard & mouse temporary not response to desktop[/color]
>
> I did want to answer with simple" me.enabled = false", but did not
> trust it because this answer seems to simple to me. So I did test
> it, and I find this strange and do not understand it.
>
> Who will test it also and tell me if this is normal behaviour or a
> bug?
> The problem is that when you pusth the button when enabled is false,
> it keeps responding to the events, so you have to push several times
> on the not locked button.
>
> Framework 1.1
>
> Cor
>
> \\\
> ' needs one button and one label on a form
> Private Sub Button1_Click(B yVal sender As System.Object, _
> ByVal e As System.EventArg s) Handles Button1.Click
> Static i As Integer
> Me.Button1.Text = "locked"
> Dim ctr As Control
> ' Me.Enabled = false did not work so
> 'I did try this but does not work either
> For Each ctr In Me.Controls
> ctr.Enabled = False
> Next
> Me.Refresh()
> Dim y As Integer
> For y = 1 To 20
> Threading.Threa d.Sleep(50)
> i = i + 50
> Me.Label1.Text = i.ToString
> Me.Refresh()
> Next
> For Each ctr In Me.Controls
> ctr.Enabled = True
> Next
> Me.Button1.Text = "Unlocked"
> End Sub
> ///[/color]

**Cor** · Nov 20 '05, 07:54 AM

Re: Repost posible Bug

Hi OHM

No I asket you to look to a posible Bug I had posted.

I was curious if I became crazy or it was a bug.

Cor

**David Scemama** · Nov 20 '05, 07:54 AM

Re: Convert VB Double to Pascal Real

The Pascal Real type, is stored on 6 bytes with a very special coding. When
you write a real value in a file, 6 bytes are written to represent the value
(obviously, no language writes the string representation of the real !). My
function reads the 6 bytes and convert them to a VB double.

I need the reverse function !

David

"One Handed Man" <Bombay@Duck.ne t> wrote in message
news:bpvjji$t6n $1@titan.btinte rnet.com...[color=blue]
> I probably have not understood you correctly, but can you not simply[/color]
convert[color=blue]
> the double to a string an then truncate the string to the correct length?
>
> As far as I am aware, a real number is simply a number which is not
> imaginary, so I dont know how this differs in a Pascal Real number. Your
> function seems to convert a string into a double but goes a long way[/color]
around.[color=blue]
> BTW, I actually tried to convert "1.2345" and it returned 0.0
>
> I'm sure Im missing something here, can you illuminate ?
>
> Regards - OHM
>
>
>
>
>
> David Scemama wrote:[color=green]
> > Hi,
> >
> > I'm writing a program using VB.NET that needs to communicate with a
> > DOS Pascal program than cannot be modified. The communication channel
> > is through some file databases, and I have a huge problem writing VB
> > Double values to the file so as the Pascal program can read them as
> > Pascal Real values.
> >
> > I've managed to find the algorithm to read the Pascal Real format and
> > convert it to a VB Double, but I cannot figure out the opposite
> > algorithm.
> >
> > Can someone help me reverse my algorithm and develop the function
> > "DoubleToRe al (ByVal Data As Double) As String"
> >
> > Here is the conversion from real to double:
> >
> > Public Function RealToDouble(By Val Data As String) As Double
> > Dim dMantissa As Double
> > Dim i As Integer
> > Dim j As Long
> > Dim k As Long
> >
> > If Len(Data) <> 6 Then
> > 'Err.Raise
> > 'exception
> > Exit Function
> > End If
> >
> > 'accumulate the mantissa
> > dMantissa = 1
> > For i = 6 To 2 Step -1
> > For j = CType(IIf(i = 6, 6, 7), Long) To 0 Step -1
> > k = k + 1
> > If (Asc(Mid$(Data, i, 1)) And CType(2 ^ j, Long)) <>
> > 0 Then dMantissa = dMantissa + 2 ^ -k
> > End If
> > Next j
> > Next i
> >
> > 'finally, assemble all the pieces into a number
> > If (Asc(Mid$(Data, 6, 1)) And &H80) = &H80 Then
> > RealToDouble = -dMantissa * 2 ^ (Asc(Mid$(Data, 1, 1)) -
> > 129) Else
> > RealToDouble = dMantissa * 2 ^ (Asc(Mid$(Data, 1, 1)) -
> > 129) End If
> >
> > Try
> > Return ([Decimal].Round(CDec(Rea lToDouble), 2))
> > Catch ex As Exception
> > 'MsgBox("RealTo Double, Conversion error: " & Data & "; " &
> > RealToDouble.To String, MsgBoxStyle.Cri tical)
> > Return 0
> > End Try
> >
> > End Function
> >
> > Thanks for your help
> > David[/color]
>
>[/color]

**One Handed Man** · Nov 20 '05, 07:54 AM

Re: Repost posible Bug

This may be because the message goes out in the message queue, the button
does not respond to it until the loop finishes, then it processes the click
( I think ).

Regards - OHM

Cor wrote:[color=blue]
> Hi OHM this was a question from cc
>[color=green]
>> how do I make keyboard & mouse temporary not response to desktop[/color]
>
> I did want to answer with simple" me.enabled = false", but did not
> trust it because this answer seems to simple to me. So I did test
> it, and I find this strange and do not understand it.
>
> Who will test it also and tell me if this is normal behaviour or a
> bug?
> The problem is that when you pusth the button when enabled is false,
> it keeps responding to the events, so you have to push several times
> on the not locked button.
>
> Framework 1.1
>
> Cor
>
> \\\
> ' needs one button and one label on a form
> Private Sub Button1_Click(B yVal sender As System.Object, _
> ByVal e As System.EventArg s) Handles Button1.Click
> Static i As Integer
> Me.Button1.Text = "locked"
> Dim ctr As Control
> ' Me.Enabled = false did not work so
> 'I did try this but does not work either
> For Each ctr In Me.Controls
> ctr.Enabled = False
> Next
> Me.Refresh()
> Dim y As Integer
> For y = 1 To 20
> Threading.Threa d.Sleep(50)
> i = i + 50
> Me.Label1.Text = i.ToString
> Me.Refresh()
> Next
> For Each ctr In Me.Controls
> ctr.Enabled = True
> Next
> Me.Button1.Text = "Unlocked"
> End Sub
> ///[/color]

**Cor** · Nov 20 '05, 07:54 AM

Re: Repost posible Bug

But should it do that?

**One Handed Man** · Nov 20 '05, 07:54 AM

Re: Repost posible Bug

I dont know the answer to this. I suggest you post the following this
specific question at top level in the group:

Regards - OHM

Cor wrote:[color=blue]
> But should it do that?[/color]

**Cor** · Nov 20 '05, 07:54 AM

Re: Convert VB Double to Pascal Real

Hi David,

I think this is a much to dificult approach for a newsgroup.
Maybe if guys like Fergus Cooney where here now, he could help you because
he likes this.

But he is not and I don't know if he will return soon.

Every byte in a file is representent by a hex value.

Can you not represent the bytes in hex form representing a normal decimal
value, maybe somebody can help you than.

Probably not me, because mostly this is not my stuff, but you never know.

Cor

**Cor** · Nov 20 '05, 07:54 AM

Re: Repost posible Bug

Hi OHM,

Putted it in the vb.language.con trols group.

Almost the private group from Herfied, I am curious what happens.

:-))

Cor

**David Scemama** · Nov 20 '05, 07:55 AM

Re: Convert VB Double to Pascal Real

The exact representation of the Pascal Real type is:
Sign Significand Exponent
Width (bits) 1 39 8

David

"David Scemama" <david.scemama@ nospam.wanadoo. fr> wrote in message
news:eFNXol2sDH A.2492@TK2MSFTN GP12.phx.gbl...[color=blue]
> The Pascal Real type, is stored on 6 bytes with a very special coding.[/color]
When[color=blue]
> you write a real value in a file, 6 bytes are written to represent the[/color]
value[color=blue]
> (obviously, no language writes the string representation of the real !).[/color]
My[color=blue]
> function reads the 6 bytes and convert them to a VB double.
>
> I need the reverse function !
>
> David
>
>
> "One Handed Man" <Bombay@Duck.ne t> wrote in message
> news:bpvjji$t6n $1@titan.btinte rnet.com...[color=green]
> > I probably have not understood you correctly, but can you not simply[/color]
> convert[color=green]
> > the double to a string an then truncate the string to the correct[/color][/color]
length?[color=blue][color=green]
> >
> > As far as I am aware, a real number is simply a number which is not
> > imaginary, so I dont know how this differs in a Pascal Real number. Your
> > function seems to convert a string into a double but goes a long way[/color]
> around.[color=green]
> > BTW, I actually tried to convert "1.2345" and it returned 0.0
> >
> > I'm sure Im missing something here, can you illuminate ?
> >
> > Regards - OHM
> >
> >
> >
> >
> >
> > David Scemama wrote:[color=darkred]
> > > Hi,
> > >
> > > I'm writing a program using VB.NET that needs to communicate with a
> > > DOS Pascal program than cannot be modified. The communication channel
> > > is through some file databases, and I have a huge problem writing VB
> > > Double values to the file so as the Pascal program can read them as
> > > Pascal Real values.
> > >
> > > I've managed to find the algorithm to read the Pascal Real format and
> > > convert it to a VB Double, but I cannot figure out the opposite
> > > algorithm.
> > >
> > > Can someone help me reverse my algorithm and develop the function
> > > "DoubleToRe al (ByVal Data As Double) As String"
> > >
> > > Here is the conversion from real to double:
> > >
> > > Public Function RealToDouble(By Val Data As String) As Double
> > > Dim dMantissa As Double
> > > Dim i As Integer
> > > Dim j As Long
> > > Dim k As Long
> > >
> > > If Len(Data) <> 6 Then
> > > 'Err.Raise
> > > 'exception
> > > Exit Function
> > > End If
> > >
> > > 'accumulate the mantissa
> > > dMantissa = 1
> > > For i = 6 To 2 Step -1
> > > For j = CType(IIf(i = 6, 6, 7), Long) To 0 Step -1
> > > k = k + 1
> > > If (Asc(Mid$(Data, i, 1)) And CType(2 ^ j, Long)) <>
> > > 0 Then dMantissa = dMantissa + 2 ^ -k
> > > End If
> > > Next j
> > > Next i
> > >
> > > 'finally, assemble all the pieces into a number
> > > If (Asc(Mid$(Data, 6, 1)) And &H80) = &H80 Then
> > > RealToDouble = -dMantissa * 2 ^ (Asc(Mid$(Data, 1, 1)) -
> > > 129) Else
> > > RealToDouble = dMantissa * 2 ^ (Asc(Mid$(Data, 1, 1)) -
> > > 129) End If
> > >
> > > Try
> > > Return ([Decimal].Round(CDec(Rea lToDouble), 2))
> > > Catch ex As Exception
> > > 'MsgBox("RealTo Double, Conversion error: " & Data & "; " &
> > > RealToDouble.To String, MsgBoxStyle.Cri tical)
> > > Return 0
> > > End Try
> > >
> > > End Function
> > >
> > > Thanks for your help
> > > David[/color]
> >
> >[/color]
>
>[/color]

**One Handed Man** · Nov 20 '05, 07:55 AM

Re: Repost posible Bug

You'll probably get the reply in German !.

Regards - OHM

Cor wrote:[color=blue]
> Hi OHM,
>
> Putted it in the vb.language.con trols group.
>
> Almost the private group from Herfied, I am curious what happens.
>
> :-))
>
> Cor[/color]

Convert VB Double to Pascal Real

Convert VB Double to Pascal Real

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