Private Const MAX_ITEMS As Integer = 11
Private Const MAX_CUSTOMERS As Integer = 14
Private Const TOTAL_PROTOTYPE_VECTORS As Integer = 10

Private Const BETA As Double = 1.0  'Small positive number.
Private Const VIGILANCE As Double = 0.6  '0 <= VIGILANCE < 1

Private PrototypeVectors As Integer = 0 'Total populated prototype vectors.

Private PrototypeVector(TOTAL_PROTOTYPE_VECTORS, MAX_ITEMS) As Integer

'Number of occupants of cluster.
Private Members(TOTAL_PROTOTYPE_VECTORS) As Integer

'Identifies which cluster a member belongs to.
Private Membership(MAX_CUSTOMERS) As Integer

Private Database As Integer(,) = New Integer(,) {{0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0}, _
                                                {0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1}, _
                                                {0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0}, _
                                                {0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1}, _
                                                {1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0}, _
                                                {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1}, _
                                                {1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0}, _
                                                {0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0}, _
                                                {0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0}, _
                                                {0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0}, _
                                                {1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0}, _
                                                {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1}, _
                                                {0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0}, _
                                                {1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1}}
												
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
    InitializeStructures()
    PerformART1()
    DisplayCustomerClusters()
    DisplayMemberships()
    DisplayCustomerDatabase()
End Sub

Private Sub InitializeStructures()
Dim Kounter1 As Integer
Dim Kounter2 As Integer
    For Kounter1 = 0 To TOTAL_PROTOTYPE_VECTORS - 1
        For Kounter2 = 0 To MAX_ITEMS - 1
            PrototypeVector(Kounter1, Kounter2) = 0
        Next
    Next

    For Kounter2 = 0 To MAX_CUSTOMERS - 1
        Membership(Kounter2) = -1
    Next
End Sub

Private Sub PerformART1()
Dim ANDResult(MAX_ITEMS) As Integer
Dim PVec As Integer
Dim MagPE As Integer
Dim MagP As Integer
Dim MagE As Integer
Dim Result As Double
Dim Test As Double
Dim Index As Integer
Dim Done As Integer = 0
Dim Count As Integer = 50
Dim Kounter As Integer
Dim TotalOnes As Integer = 0

    While Not Done
        Done = 1
        'Cycle through each of the customers.
        For Index = 0 To MAX_CUSTOMERS - 1
            'Step 3.
            For PVec = 0 To TOTAL_PROTOTYPE_VECTORS - 1
                'Check to see if this vector has any members.
                If Members(PVec) Then

                    VectorBitwiseAND(ANDResult, Database, Index, PrototypeVector, PVec)
                    
                    MagPE = VectorMagnitude(ANDResult)
                    MagP = VectorMagnitude(PrototypeVector, PVec)
                    MagE = VectorMagnitude(Database, Index)

                    Result = CDbl(MagPE) / (BETA + CDbl(MagP))

                    Test = CDbl(MagE) / (BETA + CDbl(MAX_ITEMS))

                    'MsgBox("MagPE: " + Str(CDbl(MagPE)) + " / BETA: " + Str(BETA) + _
                    '        " + MagP: " + Str(CDbl(MagP)) + " = " + Str(Result) + Chr(13) + Chr(10) + _
                    '        "MagE: " + Str(CDbl(MagE)) + " / BETA: " + Str(BETA) + _
                    '        " + MAX_ITEMS: " + Str(CDbl(MAX_ITEMS)) + " = " + Str(Test), MsgBoxStyle.OKOnly)

                    'Equation 2.
                    If Result > Test Then
                        'Test for vigilance acceptability (Equation 3).
                        If (CDbl(MagPE) / CDbl(MagE)) < VIGILANCE Then
                            Dim Old As Integer
                            'Ensure this is a different cluster.
                            If Membership(Index) <> PVec Then
                                'Move customer to the new cluster
                                Old = Membership(Index)
                                Membership(Index) = PVec

                                If Old >= 0 Then
                                    Members(Old) -= 1
                                    If Members(Old) = 0 Then
                                        PrototypeVectors -= 1
                                    End If
                                    Members(PVec) += 1
                                    'Recalculate the prototype vectors for the
                                    'old and new clusters.
                                    If (Old >= 0) And (Old < TOTAL_PROTOTYPE_VECTORS) Then
                                        UpdatePrototypeVectors(Old)
                                    End If
                                    UpdatePrototypeVectors(PVec)
                                    Done = 0
                                    Exit For 'Exit vector loop.
                                End If
                            Else
                                'Already in this cluster.
                            End If

                        End If 'for Vigilance test.

                    End If
                End If
            Next 'End of vector loop.

            'Check to see if the current vector was processed.
            If Membership(Index) = -1 Then
                'No prototype vector was found to be close to the example
                'vector.  Create a new prototype vector for this example.
                Membership(Index) = CreateNewPrototypeVector(Database, Index)
                Done = 0
            End If

        Next 'for Customers loop.
        If Not Count Then
            'Count -= 1
            Exit While
        Else
            'Not Done yet.
            Count -= 1
        End If

    End While

End Sub

Private Sub DisplayCustomerClusters()
Dim Customer As Integer
Dim Item As Integer
Dim Cluster As Integer
Dim TempString As String

    For Cluster = 0 To TOTAL_PROTOTYPE_VECTORS - 1
        TempString += Chr(13) + Chr(10)
        TempString += "ProtoType Vector: " + Str(Cluster) + ":   "
        For Item = 0 To MAX_ITEMS - 1
            TempString += Str(CInt(PrototypeVector(Cluster, Item)))
        Next
        TempString += Chr(13) + Chr(10)

        For Customer = 0 To MAX_CUSTOMERS - 1
            If Membership(Customer) = Cluster Then
                TempString += "Customer: " + Str(Customer) + ":           "
                For Item = 0 To MAX_ITEMS - 1
                    TempString += Str(CInt(Database(Customer, Item)))
                Next
                'TempString += Str(Membership(Customer))
                TempString += Chr(13) + Chr(10)
            End If
        Next

        TempString += Chr(13) + Chr(10)
    Next
    TempString += Chr(13) + Chr(10)
    Text1.Text = TempString
End Sub

Private Sub DisplayMemberships()
Dim Customer As Integer
Dim Item As Integer
Dim TempString As String
    For Customer = 0 To MAX_CUSTOMERS - 1
        TempString += "Membership: " + Str(Membership(Customer))
        TempString += Chr(13) + Chr(10)
    Next
    TempString += Chr(13) + Chr(10)
    Text1.Text += TempString
End Sub

Private Sub DisplayCustomerDatabase()
Dim Customer As Integer
Dim Item As Integer
Dim TempString As String
    For Customer = 0 To MAX_CUSTOMERS - 1
        TempString += Chr(13) + Chr(10)
        TempString += "Customer: " + Str(Customer) + ":           "
        For Item = 0 To MAX_ITEMS - 1
            TempString += Str(CInt(Database(Customer, Item)))
        Next
    Next
    Text1.Text += TempString
End Sub

Private Sub UpdatePrototypeVectors(ByVal Cluster As Integer)
Dim Item As Integer
Dim Customer As Integer
Dim First As Integer = 1
Dim ANDResult As Integer
    If Cluster >= 0 Then
        For Item = 0 To MAX_ITEMS - 1
            PrototypeVector(Cluster, Item) = 0
        Next
        For Customer = 0 To MAX_CUSTOMERS - 1
            If Membership(Customer) = Cluster Then
                If First Then
                    For Item = 0 To MAX_ITEMS - 1
                        PrototypeVector(Cluster, Item) = Database(Customer, Item)
                    Next
                    First = 0
                Else
                    For Item = 0 To MAX_ITEMS - 1
                        PrototypeVector(Cluster, Item) = (PrototypeVector(Cluster, Item) _
                                                      AndAlso Database(Customer, Item))
                    Next
                End If
            End If
        Next
    End If
End Sub

Private Function CreateNewPrototypeVector(ByVal Vector As Integer(,), _
                                            ByVal vRow As Integer) As Integer
Dim Kounter As Integer
Dim Cluster As Integer
    For Cluster = 0 To TOTAL_PROTOTYPE_VECTORS - 1
        If Members(Cluster) = 0 Then
            Exit For
        End If
    Next
    If Cluster = TOTAL_PROTOTYPE_VECTORS - 1 Then
        PrototypeVectors += 1
    End If
    For Kounter = 0 To MAX_ITEMS - 1
        'PrototypeVector(Cluster, Kounter) = Example(element)
        PrototypeVector(Cluster, Kounter) = Vector(vRow, Kounter)
    Next
    Members(Cluster) = 1
    CreateNewPrototypeVector = Cluster
End Function

Private Sub VectorBitwiseAND(ByVal Result As Integer(), ByVal v As Integer(,), _
                                                        ByVal vRow As Integer, _
                                                        ByVal w As Integer(,), _
                                                        ByVal wRow As Integer)
Dim Kounter As Integer
    For Kounter = 0 To MAX_ITEMS - 1
        'Resulting array = v(Kounter) and w(Kounter)
        Result(Kounter) = (v(vRow, Kounter) AndAlso w(wRow, Kounter))
    Next
End Sub

Private Function VectorMagnitude(ByVal Vector As Integer()) As Integer
'This function counts up all the 1's in a given vector.
Dim Kounter As Integer
Dim TotalOnes As Integer = 0
    For Kounter = 0 To MAX_ITEMS - 1
        'If Vector(Kounter) = 1 Then
        If Vector(Kounter) = True Then
            TotalOnes += 1
        End If
    Next

    VectorMagnitude = TotalOnes
End Function

Private Function VectorMagnitude(ByVal Vector As Integer(,), ByVal vRow As Integer) As Integer
'This function counts up all the 1's in a given vector.
Dim Kounter As Integer
Dim TotalOnes As Integer = 0
    For Kounter = 0 To MAX_ITEMS - 1
        If Vector(vRow, Kounter) = 1 Then
            TotalOnes += 1
        End If
    Next

    VectorMagnitude = TotalOnes
End Function