Homework17_A

Add second order regression to your statistical application.

Code VB.Net

https://drive.google.com/file/d/1ENlAz_rxyDN45E1At6IrUjRHS00-26Cr/view?usp=sharing

https://math.stackexchange.com/questions/267865/equations-for-quadratic-regression

 Public Sub calc_regressionLineSecondOrder()
        Dim s11 As Double
        Dim s12 As Double
        Dim s22 As Double
        Dim sy1 As Double
        Dim sy2 As Double

        Dim N As Integer = listOfBDataP.Count

        Dim sumX As Double
        Dim sumX_X As Double
        Dim sumPowX As Double
        Dim sumProd As Double
        Dim sumPowPow As Double
        Dim sumXY As Double
        Dim sumY As Double
        Dim sumXYPow As Double

        For Each x In listOfBDataP
            sumX += x.x1
            sumPowX += x.x1 * x.x1
            sumProd += x.x1 * x.x1 * x.x1
            sumPowPow += x.x1 * x.x1 * x.x1 * x.x1
            sumXY += x.x1 * x.x2
            sumY += x.x2
            sumXYPow += x.x2 * x.x1 * x.x1
        Next
        sumX_X = sumX * sumX

        s11 = sumPowX - (sumX_X / N)

        s12 = sumProd - (sumX * sumPowX) / N

        s22 = sumPowPow - (sumPowX * sumPowX) / N

        sy1 = sumXY - (sumY * sumX) / N

        sy2 = sumXYPow - (sumY * sumPowX) / N

        Dim meanXPow As Double = sumPowX / N

        b2 = (sy1 * s22 - sy2 * s12) / (s22 * s11 - s12 * s12)
        b3 = (sy2 * s11 - sy1 * s12) / (s22 * s11 - s12 * s12)
        b1 = current_onlineMeanY - b2 * current_onlineMeanX - b3 * meanXPow


    End Sub