form1.vb

Mastering VBNet Include Source Code

Option Strict On
Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub
    Friend WithEvents ListBox1 As System.Windows.Forms.ListBox
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.Container

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.ListBox1 = New System.Windows.Forms.ListBox()
        Me.TextBox1 = New System.Windows.Forms.TextBox()
        Me.Button1 = New System.Windows.Forms.Button()
        Me.SuspendLayout()
        '
        'ListBox1
        '
        Me.ListBox1.Font = New System.Drawing.Font("Verdana", 9.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.ListBox1.ItemHeight = 14
        Me.ListBox1.Location = New System.Drawing.Point(8, 8)
        Me.ListBox1.Name = "ListBox1"
        Me.ListBox1.Size = New System.Drawing.Size(160, 186)
        Me.ListBox1.TabIndex = 0
        '
        'TextBox1
        '
        Me.TextBox1.Font = New System.Drawing.Font("Verdana", 9.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.TextBox1.Location = New System.Drawing.Point(176, 8)
        Me.TextBox1.Multiline = True
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(264, 88)
        Me.TextBox1.TabIndex = 1
        Me.TextBox1.Text = ""
        '
        'Button1
        '
        Me.Button1.Font = New System.Drawing.Font("Verdana", 9.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Button1.Location = New System.Drawing.Point(8, 200)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(160, 32)
        Me.Button1.TabIndex = 2
        Me.Button1.Text = "Calculate Statistics"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(448, 237)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Button1, Me.TextBox1, Me.ListBox1})
        Me.Name = "Form1"
        Me.Text = "Statistics"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim SData(99) As Double
        Dim Stats() As Double
        Dim i As Integer
        Dim rnd As New System.Random()
        ListBox1.Items.Clear()
        For i = 0 To 99
            SData(i) = rnd.NextDouble() * 1000
            ListBox1.Items.Add(SData(i))
        Next
        Stats = ArrayStats(SData)
        TextBox1.Text = "Average" & vbTab & vbTab & Stats(0)
        TextBox1.Text = TextBox1.Text & vbCrLf & _
                             "Std. Deviation" & vbTab & Stats(1)
        TextBox1.Text = TextBox1.Text & vbCrLf & _
                             "Min. Value" & vbTab & Stats(2)
        TextBox1.Text = TextBox1.Text & vbCrLf & _
                             "Max. Value" & vbTab & Stats(3)
    End Sub

    Function ArrayStats(ByVal DataArray() As Double) As Double()
        Dim Results(3) As Double
        Dim Sum, SumSquares As Double
        Dim DataMin, DataMax As Double
        Dim DCount As Integer
        Dim i As Integer
        Sum = 0
        SumSquares = 0
        DCount = 0
        DataMin = System.Double.MaxValue
        DataMax = System.Double.MinValue
        For i = 0 To DataArray.GetUpperBound(0)
            Sum = Sum + DataArray(i)
            SumSquares = SumSquares + DataArray(i) ^ 2
            If DataArray(i) > DataMax Then DataMax = DataArray(i)
            If DataArray(i) < DataMin Then DataMin = DataArray(i)
            DCount = DCount + 1
        Next
        Dim Avg, StdDev As Double
        Avg = Sum / DCount
        StdDev = Math.Sqrt(SumSquares / DCount - Avg ^ 2)
        Results(0) = Avg
        Results(1) = StdDev
        Results(2) = DataMin
        Results(3) = DataMax
        ArrayStats = Results
    End Function

End Class