GoTo statement

[Linkesh]

need help
everytime i use the GoTo statement in EVB i get this comple error stating "Expected Statement"
This is the code which i reallly need to use the goto statement if there is anyother control i could use i am open for ideas


top:
x = nPHI Mod nE
y = x Mod nE
If y <> 0 And IsPrime(nE) Then
GCD = nE
Exit Function
Else
nE = nE + 1

End If


GoTo top error keeps pointing here...
i am working on EVB(embeded visual Basic)

[Mc Brain]

How about this?

Do
   x = nPHI Mod nE 
   y = x Mod nE 
   If y <> 0 And IsPrime(nE) Then 
      GCD = nE 
      Exit Function 
   Else 
      nE = nE + 1 
   End If 
Loop

[Linkesh]

hey thanks hmm just hope it doesnt go into some infinite loop thanks alot...

[Mc Brain]

It will go into an infintie loop... but so does your original code.

[Mc Brain]

No... Actually, the "Exit Function" would stop your loop.

[Linkesh]

wel currently ur rite it is going into the infinite loop maybe i got the logic wrong let me find out

[Mc Brain]

Relax... when y <> 0 And IsPrime(nE) it will exit the loop... actually it will exit the whole function.

[plenderj]

Linkesh, if you're calculating the GCD of two numbers, then this may be of intrest :

'
' What is the greatest common divisor of 2 given numbers ? (Recursive)
'
Public Function RecursiveGCD(num1 As Long, num2 As Long) As Long
    If (num1 = 1) Or (num2 = 1) Then
        RecursiveGCD = 1
    Else
        If (num1 = num2) Then
            RecursiveGCD = num1
        Else
            If (num1 > num2) Then
                RecursiveGCD = RecursiveGCD(num1 - num2, num2)
            Else
                RecursiveGCD = RecursiveGCD(num2 - num1, num1)
            End If
        End If
    End If
End Function

[Linkesh]

actually wat i am really doing is the rsa encryption and i need to find the GCD of the number

Private Function GCD(nPHI As Double) As Double
'generates a random number relatively prime to PHI

On Error Resume Next

Dim nE, y
Const N_UP = 99999999 'set upper limit of random number for E
Const N_LW = 10000000 'set lower limit of random number for E

Randomize
nE = Int((N_UP - N_LW + 1) * Rnd + N_LW)

Do
x = nPHI Mod nE
y = x Mod nE
If y <> 0 And IsPrime(nE) Then
GCD = nE

Exit Function
Else
nE = nE + 1

End If

Loop
end functon


This wat i got so far but still goes into the loop

[Linkesh]

sorry i think EVB does not support the MOD funtion for me to find modulas is there ay other way i can do this


x = nPHI Mod nE
y = x Mod nE

[Jim Brown]

None of which explains why he's getting that error in the first place! Maybe EVB doesn't support GoTo, or the syntax might be subtly different?

[Linkesh]

well we got the goto part figured out but now we are stuck in this infinte loop and i think it is because EVB cannot us the modulas funtion so does anyone know how i can find the modulas of NE without using any function....../
x = nPHI Mod nE
y = x Mod nE

[plenderj]

Linkesh, the GCD computes the greates common divisor between two numbers.
Finding the number of numbers relatively prime to a number is called the EulerPhi

Is that what you're talking about ?

Also, here's a replacement Mod function if you need it

Private Function nMod(ByRef n1 As Long, ByVal n2 As Long) As Long
    If n1 < n2 Then
        nMod = n1
        Exit Function
    Else
        nMod = nMod(n1 - n2, n2)
    End If
End Function
 
Private Sub Form_Load()
    MsgBox nMod(61, 10)
End Sub

[Linkesh]

Thanks a million guys life saver but could someone explain wat this code is actually doing
------
On Error Resume Next

Dim nE, y
Const N_UP = 99999999 'set upper limit of random number for E
Const N_LW = 10000000 'set lower limit of random number for E

Randomize
nE = Int((N_UP - N_LW + 1) * Rnd + N_LW)

[plenderj]

It makes a number between 10000000 and 99999999

[Linkesh]

do u think there is anyother way to do this cos EVB doesnt support the Random function..................

[Jim Brown]

What does EVB support?

[plenderj]

Do you have an eVB language reference ?

[Linkesh]

no thats the problem the help file is not extensive enough...

[plenderj]

Well try somethign simple like "MsgBox Rnd" and see what happens.
Also, cam you use the GetTickCount() api ?

[plenderj]

Here's a function you can use.
Its not random, but its a start.
If you can use the GetTickCount() API it would help a lot

Private Function generateRandomNumber() As Long
    Dim i As Long, n As Long: n = Second(Time): n = n + 10
    For i = 0 To (n * 2)
        generateRandomNumber = generateRandomNumber + ((Second(Time) * Minute(Time)) \ (Second(Time) + Minute(Time)))
        generateRandomNumber = generateRandomNumber + (Second(Time) * (i + (Second(Time))))
        generateRandomNumber = generateRandomNumber + (Second(Time) * Second(Time)) \ Hour(Time)
        If Second(Time) Mod 2 = 0 Then
            generateRandomNumber = generateRandomNumber + (Hour(Time) \ (Second(Time) + 1))
        Else
            generateRandomNumber = generateRandomNumber + Second(Time) + Minute(Time)
        End If
        generateRandomNumber = generateRandomNumber + Day(Time)
    Next
End Function

[Linkesh]

where do i find the GetTickCount() and do u know a way in vb to clear memory cos i think there is alot of garbage stored in it which i wish to clear