d6r2.frm

常用的数值算法的VB程序

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   4290
   ClientLeft      =   2655
   ClientTop       =   1740
   ClientWidth     =   5835
   LinkTopic       =   "Form1"
   ScaleHeight     =   4290
   ScaleWidth      =   5835
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   4200
      TabIndex        =   0
      Top             =   3600
      Width           =   1095
   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 D6R2
    'Driver for routine RAN1
    'Calculates pi statistically using volume of unit n-sphere
    PI = 3.1415926
    Dim IY(3), YPROB(3)
    IDUM& = -1
    For I = 1 To 3
        IY(I) = 0
    Next I
    Print Tab(13); "Volume of unit n-sphere, n=2,3,4"
    Print Tab(5); "# points     PI         (4/3)*PI     (1/2)*PI^2"
    For J = 1 To 15
        For K = 2 ^ (J - 1) To 2 ^ J
            x1 = RAN1(IDUM&)
            x2 = RAN1(IDUM&)
            x3 = RAN1(IDUM&)
            x4 = RAN1(IDUM&)
            If (FNC(x1, x2, 0#, 0#) < 1#) Then IY(1) = IY(1) + 1
            If (FNC(x1, x2, x3, 0#) < 1#) Then IY(2) = IY(2) + 1
            If (FNC(x1, x2, x3, x4) < 1#) Then IY(3) = IY(3) + 1
        Next K
        For I = 1 To 3
            YPROB(I) = 1# * (2 ^ (I + 1)) * IY(I) / (2 ^ J)
        Next I
        Print Tab(5); 2 ^ J;
        For M = 1 To 3
            Print Tab(15 + (M - 1) * 14); Format$(YPROB(M), "#.#####0");
        Next M
    Next J
    Print Tab(5); "actual"; Tab(15); Format$(PI, "#.#####0");
    Print Tab(29); Format$(4# * PI / 3#, "#.#####0");
    Print Tab(43); Format$(0.5 * (PI ^ 2), "#.#####0")
End Sub
Function FNC(x1, x2, x3, x4)
    FNC = Sqr(x1 ^ 2 + x2 ^ 2 + x3 ^ 2 + x4 ^ 2)
End Function
Static Function RAN1(IDUM&)
    Dim R(97)
    M1& = 259200: IA1& = 7141: IC1& = 54773: RM1 = 0.0000038580247
    M2& = 134456: IA2& = 8121: IC2& = 28411: RM2 = 0.0000074373773
    M3& = 243000: IA3& = 4561: IC3& = 51349
    If IDUM& < 0 Or IFF = 0 Then
        IFF = 1
        IX1& = (IC1& - IDUM&) Mod M1&
        IX1& = (IA1& * IX1& + IC1&) Mod M1&
        IX2& = IX1& Mod M2&
        IX1& = (IA1& * IX1& + IC1&) Mod M1&
        IX3& = IX1& Mod M3&
        For J = 1 To 97
            IX1& = (IA1& * IX1& + IC1&) Mod M1&
            IX2& = (IA2& * IX2& + IC2&) Mod M2&
            R(J) = (CSng(IX1&) + CSng(IX2&) * RM2) * RM1
        Next J
        IDUM& = 1
      End If
      IX1& = (IA1& * IX1& + IC1&) Mod M1&
      IX2& = (IA2& * IX2& + IC2&) Mod M2&
      IX3& = (IA3& * IX3& + IC3&) Mod M3&
      J = 1 + Int((97 * IX3&) / M3&)
      If J > 97 Or J < 1 Then Print "Abnormal exit": Exit Function
      RAN1 = R(J)
      R(J) = (CSng(IX1&) + CSng(IX2&) * RM2) * RM1
End Function