NaN result when converting Bytes To Megabytes - vb.net

how can I fix my method of converting Bytes To Megabytes not to get as a Result NaN.
This is my method:
Public Function BytesToMegabytes(bytes As Long) As String
Dim dblAns As Double = (bytes / 1024) / 1024
If dblAns = 0 Then
Return "0"
End If
Dim significantFigures = 4
Dim magnitude = Math.Floor(Math.Log10(dblAns)) 'In this Line I get the NaN
Dim v As Double = 10 ^ (magnitude - significantFigures + 1)
dblAns = Math.Floor(dblAns / v) * v
Dim ci = New CultureInfo("")
ci.NumberFormat.NumberDecimalSeparator = ","
ci.NumberFormat.NumberGroupSeparator = "'"
Return dblAns.ToString("#,##0.###", ci)
End Function
With Dim usedInklData = BytesToMegabytes(-3271356861) I get the correct result.
and with Dim usedInklData = BytesToMegabytes(-776150324) I get the NaN value.
Please suggest how I could correct this.
Thanks to everyone for their help.

How about you remember if your input is negative and flip the result if it is, after doing the calculation in positive numbers:
Public Function BytesToMegabytes(bytes As Long) As String
Dim isNeg = bytes < 0
If isNeg Then bytes *= -1
Dim dblAns As Double = (bytes / 1024) / 1024
If dblAns = 0 Then
Return "0"
End If
Dim significantFigures = 4
Dim magnitude = Math.Floor(Math.Log10(dblAns)) 'In this Line I get the NaN
Dim v As Double = 10 ^ (magnitude - significantFigures + 1)
dblAns = Math.Floor(dblAns / v) * v
Dim ci = New CultureInfo("")
ci.NumberFormat.NumberDecimalSeparator = ","
ci.NumberFormat.NumberGroupSeparator = "'"
If isNeg Then dblAns *= -1
Return dblAns.ToString("#,##0.###", ci)
End Function

Related

I have problem that says System.Security.Cryptography.CryptographicException: 'Bad Data. ' in vb.net when trying to import RSA parameters

Here's the code I am not sure if there's any hidden error but on runtime when trying to import the rsa parameters it pops up that error
Imports System.Security.Cryptography
Imports System.Security
Imports System.Text
Imports System.IO
Public Class RSA_Test_Form
Public FactorList As New List(Of Integer)
Public FindFactor As Long
Public PString, QString, ModulusString, ExponentString, DString, DPString,
DQString, InverseQString As String
Function ModInverse(ByVal a As Long, ByVal b As Long) As Long
Dim b0 As Long = b
Dim t As Long
Dim q As Long
Dim x0 As Long = 0
Dim x1 As Long = 1
If b = 1 Then Return 1
While a > 1
q = a \ b
t = b
b = a Mod b
a = t
t = x0
x0 = x1 - q * x0
x1 = t
End While
If x1 < 0 Then x1 += b0
Return x1
End Function
Function gcd(ByVal n1 As Long, ByVal n2 As Long) As Long
Dim i As Integer
Dim minimum As Integer
If n1 < n2 Then
minimum = n1
Else
minimum = n2
End If
For i = minimum To 1 Step -1
If n1 Mod i = 0 And n2 Mod i = 0 Then
Return i
End If
Next
Return gcd
End Function
Sub FindFactorFunction()
Dim x As Long
For x = 2 To FindFactor - 1
If FindFactor Mod x = 0 Then
FactorList.Add(x)
End If
Next
End Sub
Private Sub GenerateBTN_Click(sender As Object, e As EventArgs) Handles GenerateBTN.Click
Dim Result As Long = 0
Dim Result2 As Long = 0
Dim Result3 As Long = 0
Dim Random1, Random2 As New Random()
Dim P, Q, Modulus As Long
Dim Exponent, D, DP, DQ As New Nullable(Of Long)
Dim InverseQ As New Nullable(Of ULong)
Dim Modulus1 As Long = 0
Dim LoopCount As Integer = 0
Dim ls, ls2 As New List(Of Long)
Dim PrimeString As String
PrimeString = ""
Using MyNewStreamReader As StreamReader = New StreamReader("AllPrimes.txt")
PrimeString = MyNewStreamReader.ReadLine().ToString
MessageBox.Show(PrimeString)
While PrimeString <> "" And LoopCount <= 1249
ls.Add(Long.Parse(PrimeString))
LoopCount += 1
PrimeString = ""
PrimeString = MyNewStreamReader.ReadLine
End While
End Using
Using MyNewStreamReader2 As StreamReader = New StreamReader("AllPrimes.txt")
PrimeString = ""
PrimeString = MyNewStreamReader2.ReadLine().ToString
LoopCount = 0
MessageBox.Show(PrimeString)
While PrimeString <> ""
If LoopCount >= 1250 And LoopCount <= 2499 Then
ls2.Add(Long.Parse(PrimeString))
End If
LoopCount += 1
PrimeString = ""
PrimeString = MyNewStreamReader2.ReadLine
End While
End Using
Dim rand = Random1.Next(0, ls.Count)
Dim rand2 = Random2.Next(0, ls2.Count)
P = ls(rand)
Q = ls2(rand2)
Result3 = gcd(P, Q)
While Result3 <> 1
rand = Random1.Next(0, ls.Count)
rand2 = Random2.Next(0, ls2.Count)
P = ls(rand)
Q = ls2(rand2)
Result3 = gcd(P, Q)
End While
MessageBox.Show("P= " & P & "Q= " & Q)
Modulus = (P - 1) * (Q - 1)
Modulus1 = Modulus + 1
FindFactor = Modulus1
FindFactorFunction()
Dim Count As Integer = 0
Dim Count2 As Integer = 0
For A As Integer = 0 To FactorList.Count - 1
Result = gcd(FactorList.ElementAt(A), Modulus)
If Result = 1 Then
Count += 1
End If
Next
Dim PositionArray(Count) As Integer
Count = 0
For A As Integer = 0 To FactorList.Count - 1
Result = gcd(FactorList.ElementAt(A), Modulus)
If Result = 1 Then
PositionArray(Count) = FactorList.ElementAt(A)
Count += 1
End If
Next
Dim Number1, Number2 As Long
Dim GetResult As Boolean = False
Count = 0
If PositionArray.Count = 2 Then
Exponent = PositionArray(0)
D = PositionArray(1)
Else
While GetResult = False And Count <> PositionArray.Count
For Count = 0 To PositionArray.Count - 1
For Count2 = Count + 1 To PositionArray.Count - 1
Number1 = PositionArray(Count)
Number2 = PositionArray(Count2)
Result2 = Number1 * Number2 Mod Modulus
If Result2 = 1 Then
GetResult = True
End If
If GetResult = True Then
Exit While
End If
Next
Next
End While
End If
Dim Selection As Integer = MessageBox.Show(Number1 & "=E And D= " & Number2, "Information", MessageBoxButtons.OKCancel, MessageBoxIcon.Information)
If Selection = DialogResult.OK Then
Exponent = Number1
D = Number2
DP = D * P
DQ = D * Q
InverseQ = ModInverse(Q, P)
MessageBox.Show("DP= " & DP)
MessageBox.Show("DQ= " & DQ)
MessageBox.Show("InverseQ= " & InverseQ)
In here when generating RSA numbers, I can not always get the correct numbers so i am using this website to check that i have get the correct RSA numbers and the D and Exponent was not = 0
Exponent=e
Everytime I get Exponent and D, I will always use this website to check P,Q,Exponent and D to make sure it's correct
https://www.cs.drexel.edu/~jpopyack/IntroCS/HW/RSAWorksheet.html
End If
If Exponent.HasValue And D.HasValue Then
PString = P.ToString
QString = Q.ToString
ModulusString = Modulus.ToString
ExponentString = Exponent.ToString
DString = D.ToString
DPString = DP.ToString
DQString = DQ.ToString
InverseQString = InverseQ.ToString
In here all D,P,Q,DP,DQ,Exponent,Modulus,InverseQ value has been calculated and checked
End If
End Sub
Private Sub Number2ByteConverterBTN_Click(sender As Object, e As EventArgs) Handles Number2ByteConverterBTN.Click
If it's possible try check the coding here, perhaps this place was the place that i do it wrongly
I initially thought of using BitCoverter.GetBytes() to convert the long and Ulong datatype value
But in the end, the bitconverter.getbytes() doesn't work for me so i have to first convert all those long and ulong data type values into string then use BYTE.PARSE() to convert the string into byte value
That's how i do it
If let's any experts here confirmed that the coding above worked and all the values are correct then try to check is there any potential error here
Dim PByte, QByte, ModulusByte, ExponentByte, DByte, DPByte, DQByte, InverseQByte As Byte()
ReDim PByte(PString.Count)
ReDim QByte(QString.Count)
ReDim ModulusByte(ModulusString.Count)
ReDim ExponentByte(ExponentString.Count)
ReDim DByte(DString.Count)
ReDim DPByte(DPString.Count)
ReDim DQByte(DQString.Count)
ReDim InverseQByte(InverseQString.Count)
Dim TempPByte, TempQByte, TempModulusByte, TempExponentByte, TempDByte As New Byte
Dim StringBuilder As New StringBuilder
Dim StringBuilder2 As New StringBuilder
Dim StringBuilder3 As New StringBuilder
Dim StringBuilder4 As New StringBuilder
Dim StringBuilder5 As New StringBuilder
Dim StringBuilder6 As New StringBuilder
Dim StringBuilder7 As New StringBuilder
Dim StringBuilder8 As New StringBuilder
For i As Integer = 0 To PString.Length - 1
PByte(i) = Byte.Parse(PString.ElementAt(i))
StringBuilder.Append(PByte(i).ToString)
Next
For i As Integer = 0 To QString.Length - 1
QByte(i) = Byte.Parse(QString.ElementAt(i))
StringBuilder2.Append(QByte(i).ToString)
Next
For i As Integer = 0 To ModulusString.Length - 1
ModulusByte(i) = Byte.Parse(ModulusString.ElementAt(i))
StringBuilder3.Append(ModulusByte(i).ToString)
Next
For i As Integer = 0 To ExponentString.Length - 1
ExponentByte(i) = Byte.Parse(ExponentString.ElementAt(i))
StringBuilder4.Append(ExponentByte(i).ToString)
Next
For i As Integer = 0 To DString.Length - 1
DByte(i) = Byte.Parse(DString.ElementAt(i))
StringBuilder5.Append(DByte(i).ToString)
Next
For i As Integer = 0 To DPString.Length - 1
DPByte(i) = Byte.Parse(DPString.ElementAt(i))
StringBuilder6.Append(DPByte(i).ToString)
Next
For i As Integer = 0 To DQString.Length - 1
DQByte(i) = Byte.Parse(DQString.ElementAt(i))
StringBuilder7.Append(DQByte(i).ToString)
Next
For i As Integer = 0 To InverseQString.Length - 1
InverseQByte(i) = Byte.Parse(InverseQString.ElementAt(i))
StringBuilder8.Append(InverseQByte(i).ToString)
Next
Dim MyRSAParams As New RSAParameters
MyRSAParams.P = PByte
MyRSAParams.Q = QByte
MyRSAParams.Exponent = ExponentByte
MyRSAParams.Modulus = ModulusByte
MyRSAParams.D = DByte
MyRSAParams.DP = DPByte
MyRSAParams.DQ = DQByte
MyRSAParams.InverseQ = InverseQByte
Dim MyRSA As RSA
MyRSA = RSA.Create()
MyRSA.ImportParameters(MyRSAParams)
End Sub
Private Sub RSA_Test_Form_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim temp, temp2 As Integer
temp = gcd(1, 2)
temp2 = gcd(2, 3)
FindFactor = 0
End Sub
End Class
What I am trying to do in the generate button was to create the suitable parameters for RSA.
The parameters I was actually able to generate them but in either ULong or Long data type.
When i first convert them into array of Bytes I have considered to use BitConverter but it doesn't work at least in my case.
The only way i am only able to make them into array of Bytes was by making the ULong or Long data type variable into string.
Then convert those string into Byte then put them into ByteArray
I hope it was correct but it is out of my reach for now.
Any ideas on how can i make the parameter data to be accepted as rsa parameter?

VBA Split array

I have the following code:
Sub UpdateBlock()
'Define empty variables for each attribute
Dim ent As AcadEntity
Dim oBkRef As AcadBlockReference
Dim Insertpoints As Variant
Dim A As Double
Dim tag As String
Dim material As String
Dim actualLength As String
Dim cutOff As Double
Dim cutLengths As Double
Dim totalLengths As Double
Dim weight As Double
Dim purchaseLength As Double
Dim decimalLength As Double
Dim lengthWeight As Double
Dim totalLengthWeight As Double
Dim cutLengthWeight As Double
Dim cutWeight As Double
Dim order As Double
Dim feet As Double
Dim inches As Double
Dim fraction As Double
Dim fracVal As Variant
'First we go over every object in the modelspace
For Each ent In ThisDrawing.ModelSpace
'Check if the object is a block
If ent.ObjectName = "AcDbBlockReference" Then
Set oBkRef = ent
'If the object is a block then check if its the block we are looking for
If oBkRef.EffectiveName = "AUTOTAG-MATERIAL" Then
A = A + 1
'Get Current Attributes
attlist = oBkRef.GetAttributes
For i = LBound(attlist) To UBound(attlist)
Select Case attlist(i).TagString
Case "ACTUAL-LENGTH"
actualLength = attlist(i).TextString
Case "PURCHASE-LENGTH"
purchaseLength = attlist(i).TextString
Case "CUT-OFF"
cutOff = Frac2Num(attlist(i).TextString)
Case "DECIMAL-LENGTH"
feet = Split(actualLength)(0)
inches = Split(actualLength)(1)
fracVal = Split(actualLength)(2)
If Not IsNull(Split(actualLength)(2)) Then
fraction = Frac2Num(fracVal)
Else
fraction = 0
End If
decimalLength = Round((((feet * 12) + (inches + fraction)) / 12) - cutOff, 2)
attlist(i).TextString = decimalLength
Case "WEIGHT"
weight = attlist(i).TextString
Case "CUT-WEIGHT"
cutWeight = weight * decimalLength
attlist(i).TextString = cutWeight
Case "LENGTH-WEIGHT"
lengthWeight = weight * purchaseLength
attlist(i).TextString = lengthWeight
Case "TOTAL-LENGTHS"
totalLengths = attlist(i).TextString
Case "CUT-LENGTHS"
cutLength = attlist(i).TextString
Case "TOTAL-LENGTH-WEIGHT"
totalLengthWeight = lengthWeight * totalLengths
attlist(i).TextString = totalLengthWeight
Case "CUT-LENGTH-WEIGHT"
totalCutWeight = lengthWeight * cutLength
attlist(i).TextString = totalCutWeight
End Select
Next
End If
End If
Next ent
End Sub
Function Frac2Num(ByVal X As String) As Double
Dim P As Integer, N As Double, Num As Double, Den As Double
X = Trim$(X)
P = InStr(X, "/")
If P = 0 Then
N = Val(X)
Else
Den = Val(Mid$(X, P + 1))
If Den = 0 Then Error 11 ' Divide by zero
X = Trim$(Left$(X, P - 1))
P = InStr(X, " ")
If P = 0 Then
Num = Val(X)
Else
Num = Val(Mid$(X, P + 1))
N = Val(Left$(X, P - 1))
End If
End If
If Den <> 0 Then
N = N + Num / Den
End If
Frac2Num = N
End Function
The variable fraction / fracVal comes from a tag in AutoCAD that is a length, that will always be at least "0 0", but may be "0 0 0" it is a length in feet, inches, and fractional inches. So some possible values could be "8 5", "16 11 11/16", "0 5 3/8" etc.
What I need is a check for when the fraction is not there.
Any suggestions?
I would split the string on the space and see if the ubound of the resulting array is 2. So something like this
If Ubound(Split(thisString, " ")) = 2 then
'fractional part is present
End If
Another option is the Like Operator:
If thisString Like "#* #* #*/#*" Then
# matches any single digit (0–9) and * matches zero or more characters.
but since you split the string anyway, I would store the result of the split in a variable and check the number of items in it with UBound as shown in the other answer.

Performance loss in VB.net equivalent of light weight conversion from hex to byte

I have read through the answers here https://stackoverflow.com/a/14332574/44080
I've also tried to produce equivalent VB.net code:
Option Strict ON
Public Function ParseHex(hexString As String) As Byte()
If (hexString.Length And 1) <> 0 Then
Throw New ArgumentException("Input must have even number of characters")
End If
Dim length As Integer = hexString.Length \ 2
Dim ret(length - 1) As Byte
Dim i As Integer = 0
Dim j As Integer = 0
Do While i < length
Dim high As Integer = ParseNybble(hexString.Chars(j))
j += 1
Dim low As Integer = ParseNybble(hexString.Chars(j))
j += 1
ret(i) = CByte((high << 4) Or low)
i += 1
Loop
Return ret
End Function
Private Function ParseNybble(c As Char) As Integer
If c >= "0"C AndAlso c <= "9"C Then
Return c - "0"C
End If
c = ChrW(c And Not &H20)
If c >= "A"C AndAlso c <= "F"C Then
Return c - ("A"C - 10)
End If
Throw New ArgumentException("Invalid nybble: " & c)
End Function
Can we remove the compile errors in ParseNybble without introducing data conversions?
Return c - "0"c Operator '-' is not defined for types 'Char' and 'Char'
c = ChrW(c And Not &H20) Operator 'And' is not defined for types 'Char' and 'Integer'
As it stands, no.
However, you could change ParseNybble to take an integer and pass AscW(hexString.Chars(j)) to it, so that the data conversion takes place outside of ParseNybble.
This solution is much much faster than all the alternative i have tried. And it avoids any ParseNybble lookup.
Function hex2byte(s As String) As Byte()
Dim l = s.Length \ 2
Dim hi, lo As Integer
Dim b(l - 1) As Byte
For i = 0 To l - 1
hi = AscW(s(i + i))
lo = AscW(s(i + i + 1))
hi = (hi And 15) + ((hi And 64) >> 6) * 9
lo = (lo And 15) + ((lo And 64) >> 6) * 9
b(i) = CByte((hi << 4) Or lo)
Next
Return b
End Function

Type mismatch error when generating random numbers

When I generate random numbers, I sometimes get (not always) the following error:
Run-time error '13': type mismatch.
on line Z = Sqr(time) * Application.NormSInv(Rnd()) (and the end of the second for loop).
Why do I get this error?
I think it has something to do with the fact that it contains Rnd().
Sub asiancall()
'defining variables
Dim spot As Double
Dim phi As Integer
Dim rd_cont As Double
Dim rf_cont As Double
Dim lambda As Double
Dim muY As Double
Dim sigmaY As Double
Dim vol As Double
Dim implied_vol As Double
Dim spotnext As Double
Dim time As Double
Dim sum As Double
Dim i As Long
Dim mean As Double
Dim payoff_mean As Double
Dim StDev As Double
Dim K As Double
Dim Egamma0 As Double
Dim mulTv As Double
Dim prod As Double
Dim U As Double
Dim Pois As Double
Dim Q As Double
Dim Z As Long
Dim gamma As Double
Dim payoff As Double
Dim payoff_sum As Double
Dim secondmoment As Double
Dim j As Long
Dim N As Long
Dim mu As Double
Dim sum1 As Double
'read input data
spot = Range("B3")
rd_cont = Range("C5")
rf_cont = Range("C4")
muY = Range("B17")
sigmaY = Range("B18")
lambda = Range("B16")
K = Range("F33")
implied_vol = Range("F35")
N = Range("F34")
vol = Range("B6")
'calculations
sum_BS = 0
payoff_BS = 0
mean_BS = 0
secondmoment_BS = 0
For j = 1 To N
spotnext = spot
spotnext_BS = spot
time = 0
sum1 = 0
time = 184 / (360 * 6)
For i = 1 To 6
' 'Merton uitvoeren
Egamma0 = Exp(muY + sigmaY * sigmaY * 0.5) - 1
mu = rd_cont - rf_cont
mulTv = (mu - lambda * Egamma0 - implied_vol * implied_vol * 0.5) * time
sum = 0
prod = 1
Do While sum <= time
U = Rnd()
Pois = -Log(U) / lambda
sum = sum + Pois
Q = Application.NormInv(Rnd(), muY, sigmaY)
gamma = Exp(Q) - 1
prod = prod * (1 + gamma)
Loop
prod = prod / (1 + gamma)
Z = Sqr(time) * Application.NormSInv(Rnd())
spotnext = spotnext * Exp(mulTv + implied_vol * Z) * prod
sum1 = sum1 + spotnext
Next i
mean = sum1 / 6
payoff = Application.Max(mean - K, 0)
payoff_sum = payoff_sum + payoff
secondmoment = secondmoment + payoff * payoff
Next j
Following up on the community wiki answer I posted, a possible solution is this:
Function RndExcludingZero()
Do
RndExcludingZero = Rnd()
Loop While RndExcludingZero = 0
End Function
Usage:
Z = Sqr(time) * Application.NormSInv(RndExcludingZero())
Rnd() returns values >=0 and <1.
At some point it is bound to return 0. When given 0 as input in Excel, NormSInv returns the #NUM!
Excel error.* When called in VBA via Application.NormSInv(0), it returns a Variant of subtype Error with value "Error 2036" (equivalent to the #NUM! Excel error).
Such Variant/Errors cannot be implicitly coerced to a numerical value (which is what the * operator expects) and thus in this case, you will get the type mismatch error.
You will only get this error when Rnd() happens to return 0, which is consistent with your observation that the error occurs only sometimes.
* This was first remarked by user3964075 in a now defunct comment to the question.

Normal Distributed Random Number in VB.NET

Is there anybody know how to make normal distributed random number in vb.net?
thank you
From this forum post :
Usage:
GaussNumDist(Mean, Standard Deviation, Sample Size)
Code example below, which will populate GaussNumArray() with the sample of numbers, whose distribution will have the mean and standard deviation specified:
Imports System.Math
Module Module1
Friend GaussNumArray() As Double
Friend intICell As Long
Friend Function GaussNumDist(ByVal Mean As Double, ByVal StdDev As Double, ByVal SampleSize As Integer)
intICell = 1 'Loop variable
ReDim GaussNumArray(SampleSize)
Do While (intICell < (SampleSize + 1))
Call NumDist(Mean, StdDev)
Application.DoEvents()
Loop
End Function
Sub NumDist(ByVal meanin As Double, ByVal sdin As Double)
'---------------------------------------------------------------------------------
'Converts uniform random numbers over the region 0 to 1 into Gaussian distributed
'random numbers using Box-Muller algorithm.
'Adapted from Numerical Recipes in C
'---------------------------------------------------------------------------------
'Defining variables
Dim dblR1 As Double
Dim dblR2 As Double
Dim mean As Double
Dim var As Double
Dim circ As Double
Dim trans As Double
Dim dblY1 As Double
Dim dblY2 As Double
Dim Pi As Double
Pi = 4 * Atan(1)
'Get two random numbers
dblR1 = (2 * UniformRandomNumber()) - 1
dblR2 = (2 * UniformRandomNumber()) - 1
circ = (dblR1 ^ 2) + (dblR2 ^ 2) 'Radius of circle
If circ >= 1 Then 'If outside unit circle, then reject number
Call NumDist(meanin, sdin)
Exit Sub
End If
'Transform to Gaussian
trans = Sqrt(-2 * Log(circ) / circ)
dblY1 = (trans * dblR1 * sdin) + meanin
dblY2 = (trans * dblR2 * sdin) + meanin
GaussNumArray(intICell) = dblY1 'First number
'Increase intICell for next random number
intICell = (intICell + 1)
GaussNumArray(intICell) = dblY2 'Second number
'Increase intICell again ready for next call of ConvertNumberDistribution
intICell = (intICell + 1)
End Sub
Friend Function UniformRandomNumber() As Double
'-----------------------------------------------------------------------------------
'Outputs random numbers with a period of > 2x10^18 in the range 0 to 1 (exclusive)
'Implements a L'Ecuyer generator with Bays-Durham shuffle
'Adapted from Numerical Recipes in C
'-----------------------------------------------------------------------------------
'Defining constants
Const IM1 As Double = 2147483563
Const IM2 As Double = 2147483399
Const AM As Double = (1.0# / IM1)
Const IMM1 As Double = (IM1 - 1.0#)
Const IA1 As Double = 40014
Const IA2 As Double = 40692
Const IQ1 As Double = 53668
Const IQ2 As Double = 52774
Const IR1 As Double = 12211
Const IR2 As Double = 3791
Const NTAB As Double = 32
Const NDIV As Double = (1.0# + IM1 / NTAB)
Const ESP As Double = 0.00000012
Const RNMX As Double = (1.0# - ESP)
Dim iCell As Integer
Dim idum As Double
Dim j As Integer
Dim k As Long
Dim temp As Double
Static idum2 As Long
Static iy As Long
Static iv(NTAB) As Long
idum2 = 123456789
iy = 0
'Seed value required is a negative integer (idum)
Randomize()
idum = (-Rnd() * 1000)
'For loop to generate a sequence of random numbers based on idum
For iCell = 1 To 10
'Initialize generator
If (idum <= 0) Then
'Prevent idum = 0
If (-(idum) < 1) Then
idum = 1
Else
idum = -(idum)
End If
idum2 = idum
For j = (NTAB + 7) To 0
k = ((idum) / IQ1)
idum = ((IA1 * (idum - (k * IQ1))) - (k * IR1))
If (idum < 0) Then
idum = (idum + IM1)
End If
If (j < NTAB) Then
iv(j) = idum
End If
Next j
iy = iv(0)
End If
'Start here when not initializing
k = (idum / IQ1)
idum = ((IA1 * (idum - (k * IQ1))) - (k * IR1))
If (idum < 0) Then
idum = (idum + IM1)
End If
k = (idum2 / IQ2)
idum2 = ((IA2 * (idum2 - (k * IQ2))) - (k * IR2))
If (idum2 < 0) Then
idum2 = idum2 + IM2
End If
j = (iy / NDIV)
iy = (iv(j) - idum2)
iv(j) = idum
If (iy < 1) Then
iy = (iy + IMM1)
End If
temp = AM * iy
If (temp <= RNMX) Then
'Return the value of the random number
UniformRandomNumber = temp
End If
Next iCell
End Function
End Module
You can use following line
Dim x1 as Double = MathNet.Numerics.Distributions.Normal.Sample(MEAN, STDEV)
Math.Net Numeric package can be installed using following NuGet command
Install-Package MathNet.Numerics -Version 4.9.0
You can found more information on NuGet site