VBA - Excel custom defined function gives me datatype error

Question

This is my first time coding in VBA. Can anyone help me? It gives me unvalid datatype input. Where is the bug? Thank you.

Public Function prum(Data1 As Range) As Double()
    Dim X
    Dim result(1) As Double
    Dim count As Integer
    Dim i As Integer
    X = Data1
    count = UBound(X)

    result(0) = 0
    result(1) = 0

    For i = 1 To UBound(X)
        result(0) = X(i) + result(0)
    Next i
    result(0) = result(0) / count


    For i = 1 To UBound(X)
        result(1) = (X(i) - result(0)) * (X(i) - result(0)) + result(1)
    Next i

    result(1) = Sqr(result(1) / (count - 1) / count)


    prum = result
End Function

Answer 1

The problem is that X is a 2 dimensional array. You can convert the range values to a 1D array using Application.Transpose .

X = Application.Transpose(Data1)