Using seed to generate random numbers if VBA

[afndst]

I am having trouble with the following code to get repeated series of random numbers using a seed value. The series obtained are always different.

Option Base 1
Option Explicit
Function MyRnd(n, Optional seed)
Dim x() As Double
ReDim x
' Dim xc As Integer
' Dim xp As Double
Dim i As Integer
' Dim s As Double



If IsMissing(seed) Then

For i = 1 To n
x(i) = Rnd
Next i
Else
Randomize seed
For i = 1 To n
x(i) = Rnd
Next i
End If

MyRnd = WorksheetFunction.Transpose(x)

End Function

 

[pgc01]

Hi

Check the help.

If you want to repeat the random number sequence for the seed value, you have to call rnd with a negative value before, like:

...
Else
    
    Rnd -1
    Randomize seed
...

also the redim of the array should start at 1, you are not using element 0:

ReDim x(1 To n)

 

[afndst]

Thank you very much. Problem solved:

Function xx0(n, seed, Optional out = 0)
Dim x()
ReDim x(1 To n)

Rnd (-1)
Randomize seed


For i = 1 To n
x(i) = Rnd()
Next i

If out = 0 Then
xx0 = WorksheetFunction.Transpose(x)
Else
xx0 = WorksheetFunction.Transpose(x(out))
End If

End Function

 

[pgc01]

You're welcome. Thanks for the feedback.