ArrayAvg - The average of an array of any numeric type

' The average of an array of any numeric type
'
' Example:
'   Dim arr As Integer() = {3, 7, 8, 2, 0, 9}
'   MessageBox.Show(ArrayAvg(arr))

Function ArrayAvg(ByVal arr As Array) As Double
    Return ArrayAvg(arr, arr.GetLowerBound(0), arr.GetUpperBound(0))
End Function

' This overloaded version allows you to specify which portion of the array 
' should be considered
Function ArrayAvg(ByVal arr As Array, ByVal first As Integer, _
    ByVal last As Integer) As Double
    Dim i As Integer
    Dim sum As Double

    For i = first To last
        sum += CType(arr(i), Double)
    Next

    ' return the average
    Return sum / ((last + 1) - first)
End Function