VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   5640
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   5280
   LinkTopic       =   "Form1"
   ScaleHeight     =   5640
   ScaleWidth      =   5280
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   3480
      TabIndex        =   0
      Top             =   4800
      Width           =   1335
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub Command1_ClicK()
    'PROGRAM D4R5
    'Driver for routine BETA
    Open "D:\VB常用數值算法集\DATA\FNCVAL.DAT" For Input As #1
    Do
      Line Input #1, Text$
    Loop While Text$ <> "Beta Function"
    Line Input #1, NVAL$
    NVAL = Val(NVAL$)
    Print Text$
    Print
    Print "    W       Z            Actual          BETA(W,Z)"
    For I = 1 To NVAL
        Line Input #1, DUM$
        W = Val(Mid(DUM$, 1, 6))
        Z = Val(Mid(DUM$, 7, 6))
        Value = Val(Mid(DUM$, 13))
        Print Tab(4); Format$(W, "#0.0");
        Print Tab(12); Format$(Z, "#0.0");
        Print Tab(23); Format$(Value, ".000000E+00");
        Print Tab(40); Format$(BETA(W, Z), ".000000E+00")
    Next I
    Close #1
End Sub
Function BETA(Z, W)
    BETA = Exp(GAMMLN(Z) + GAMMLN(W) - GAMMLN(Z + W))
End Function
   Function GAMMLN(XX)
      Dim COF(6)
      COF(1) = 76.18009173
      COF(2) = -86.50532033
      COF(3) = 24.01409822
      COF(4) = -1.231739516
      COF(5) = 0.00120858003
      COF(6) = -0.00000536382
      STP = 2.50662827465
      HALF = 0.5
      ONE = 1#
      FPF = 5.5
      X = XX - ONE
      TMP = X + FPF
      TMP = (X + HALF) * Log(TMP) - TMP
      SER = ONE
      For J = 1 To 6
          X = X + ONE
          SER = SER + COF(J) / X
    Next J
      GAMMLN = TMP + Log(STP * SER)
   End Function