Attribute VB_Name = "Mod1DMinimization"
Option Explicit

 'Public Variables for minimization routines
    Public FA As Double
    Public FB As Double
    Public FC As Double
    Public AX As Double
    Public BX As Double
    Public CX As Double
    Public A As Double
    Public B As Double
    Public C As Double
    Public Xmin As Double
    Public Gold As Double
    
Public Sub MNBRAKCV(AX, BX, NumOfLocs)
Dim Gold As Single
Dim glimit As Single
Dim tiny As Double
Dim DUM As Double
Dim DONE As Integer
Dim Q As Double
Dim R As Double
Dim U As Double
Dim ULIM As Double
Dim FU As Double
Gold = 1.618034
glimit = 500
tiny = 1 * 10 ^ -20
FA = BBLikelihoodVar(AX, NumOfLocs)
FB = BBLikelihoodVar(BX, NumOfLocs)
If FB > FA Then
    DUM = AX
    AX = BX
    BX = DUM
    DUM = FB
    FB = FA
    FA = DUM
End If
CX = BX + Gold * (BX - AX)
If CX < 0 Then
    CX = BX - BX * 0.99
End If
FC = BBLikelihoodVar(CX, NumOfLocs)
A = AX
B = BX
C = CX
Do While FB >= FC
    R = (BX - AX) * (FB - FC)
    Q = (BX - CX) * (FB - FA)
    DUM = Q - R
        If Abs(DUM) < tiny Then DUM = tiny
        
            U = BX - ((BX - CX) * Q - (BX - AX) * R) / (2 * DUM)
            ULIM = BX + glimit * (CX - BX)
            If (BX - U) * (U - CX) > 0 Then
                FU = BBLikelihoodVar(U, NumOfLocs)
                    If FU < FC Then
                        AX = BX
                        FA = FB
                        BX = U
                        FB = FU
                        Exit Sub
                    ElseIf FU > FB Then
                        CX = U
                        FC = FU
                        Exit Sub
                    End If
                U = CX + Gold * (CX - BX)
                FU = BBLikelihoodVar(U, NumOfLocs)
            ElseIf (CX - U) * (U - ULIM) > 0 Then
                FU = BBLikelihoodVar(U, NumOfLocs)
                    If FU < FC Then
                        BX = CX
                        CX = U
                        U = CX + Gold * (CX - BX)
                        FB = FC
                        FC = FU
                        FU = BBLikelihoodVar(U, NumOfLocs)
                    End If
            ElseIf (U - ULIM) * (ULIM - CX) >= 0 Then
                U = ULIM
                FU = BBLikelihoodVar(U, NumOfLocs)
            Else
                U = CX + Gold * (CX - BX)
                FU = BBLikelihoodVar(U, NumOfLocs)
            End If
            AX = BX
            BX = CX
            CX = U
            FA = FB
            FB = FC
            FC = FU
Loop
End Sub
Public Sub goldenCV(AX, BX, CX, TOL, NumOfLocs)
Dim R As Single
Dim C As Single
Dim X0 As Double
Dim X1 As Double
Dim X2 As Double
Dim X3 As Double
Dim F1 As Double
Dim F2 As Double
R = 0.61803399
C = 0.38196602
X0 = AX
X3 = CX
If Abs(CX - BX) > Abs(BX - AX) Then
    X1 = BX
    X2 = BX + C * (CX - BX)
Else
    X2 = BX
    X1 = BX - C * (BX - AX)
End If
F1 = BBLikelihoodVar(X1, NumOfLocs)
F2 = BBLikelihoodVar(X2, NumOfLocs)
Do While Abs(X2 - X0) > TOL * (Abs(X1) + Abs(X2))
    If F2 < F1 Then
        X0 = X1
        X1 = X2
        X2 = R * X1 + C * X3
        F1 = F2
        F2 = BBLikelihoodVar(X2, NumOfLocs)
    Else
        X3 = X2
        X2 = X1
        X1 = R * X2 + C * X0
        F2 = F1
        F1 = BBLikelihoodVar(X1, NumOfLocs)
    End If
Loop
If F1 < F2 Then
    Gold = F1
    Xmin = X1
Else
    Gold = F2
    Xmin = X2
End If
End Sub
Public Function BBLikelihoodVar(Var, NumOfLocs)
Dim I As Double
Dim Location As Double
Dim DensityAtI As Double
Dim LnDensityAtI As Double
Dim SumLogDensity As Double

Dim BBVar As Double
Dim sqdist As Double
Dim TimeI As Double
Dim TotalTimeI As Double
Dim MeanX As Double
Dim MeanY As Double
Dim Alpha As Double
Dim Dist2 As Double
Dim Stand As Double
Dim TelemVar As Double

BBVar = Var
TelemVar = TelemErrorStdDev ^ 2
I = 1
'Calculate density at each location
    ReDim densityarrayati(NumOfLocs)
    DensityAtI = 0
    Dim count As Integer
    count = (NumOfLocs - 1) / 2
Do Until I > NumOfLocs - 2
    TimeI = SortedXYArray(I, 2) - SortedXYArray(I - 1, 2)
    TotalTimeI = SortedXYArray(I + 1, 2) - SortedXYArray(I - 1, 2)
    MeanX = (TimeI / TotalTimeI) * (SortedXYArray(I + 1, 0) - SortedXYArray(I - 1, 0)) + SortedXYArray(I - 1, 0)
    MeanY = (TimeI / TotalTimeI) * (SortedXYArray(I + 1, 1) - SortedXYArray(I - 1, 1)) + SortedXYArray(I - 1, 1)
    Dist2 = ((SortedXYArray(I, 0) - MeanX) ^ 2 + (SortedXYArray(I, 1) - MeanY) ^ 2)
    Alpha = TimeI / TotalTimeI
    Stand = TotalTimeI * Alpha * (1 - Alpha) * BBVar + ((Alpha ^ 2 + (1 - Alpha) ^ 2) * TelemVar)
    DensityAtI = 1 / (2 * Pi * Stand) * Exp(-0.5 * (Dist2 / (Stand)))
    If DensityAtI = 0 Then
        MsgBox "density at i = 0"
    End If
    LnDensityAtI = Log(DensityAtI)
    SumLogDensity = LnDensityAtI + SumLogDensity
I = I + 2
Loop
BBLikelihoodVar = -SumLogDensity
End Function