ESEMPIO IN VB.NET PER CALCOLARE MEDIA E VARIANZA

Qui di seguito, è riportato un esempio di calcolo della running mean, della running variance e della running covariance.

Public Class Form1
        Dim Count As Integer
        Dim AvgL As Double
        Dim AvgK As Double
        Dim PrevAvgL As Double
        Dim PrevAvgK As Double
        Dim VarL As Double
        Dim VarK As Double
        Dim Cov As Double
        Dim L As New List(Of Integer) 'List of exams by L             
End Class

    Private Sub Button1_Click(sender As Object, e As EventArgs)Handles Button1.Click

        Dim K As New List(Of Integer)  'List of exams by K          

 

        L.Add(28)

        L.Add(30)

        L.Add(23)

        L.Add(27)

        L.Add(28)

        L.Add(23)

        L.Add(30)

L.Add(27)

L.Add(25)

        K.Add(18)

        K.Add(22)

        K.Add(23)

        K.Add(27)

        K.Add(24)

        K.Add(25)

        K.Add(28)

                K.Add(21)

                K.Add(19)

                For i As Integer = 0 To L.Count - 1

            PrevAvgL = AvgL

            PrevAvgK = AvgK

            Count = Count + 1

            AvgL = ((Count-1)*AvgL+L(i))/Count

            AvgK = ((Count-1)*AvgK+K(i))/Count

            VarL = ((Count-1)*VarL+(L(i)-PrevAvgL)*(L(i)-AvgL))/Count

            VarK = ((Count-1)*VarK+(K(i)-PrevAvgK)*(K(i)-AvgK))/Count

            Cov = ((Count-1)*Cov+(L(i)-PrevAvgL)*(K(i)*AvgK))/Count

    End Sub