d10r2.frm

VB常用数值算法集 内含有解线性代数方程组

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   4110
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   4785
   LinkTopic       =   "Form1"
   ScaleHeight     =   4110
   ScaleWidth      =   4785
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   3120
      TabIndex        =   0
      Top             =   3480
      Width           =   1215
   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 D10R2
    'Driver for routine ZBRAC
    Print
    Print Tab(3); "Bracketing values:         Function values:"
    Print
    Print "    X1        X2       BESSJ0(X1)      BESSJ0(X2)"
    Print Tab(5)
    For I = 1 To 10
        X1 = I
        X2 = X1 + 1
        Call ZBRAC(X1, X2, SUCCES)
        If SUCCES Then
            Print Tab(4); Format$(X1, "##.00");
            Print Tab(14); Format$(X2, "##.00");
            Print Tab(24); Format$(BESSJ0(X1), "0.#####0");
            Print Tab(42); Format$(BESSJ0(X2), "0.#####0")
        End If
    Next I
 End Sub
Function FUN(X)
    FUN = BESSJ0(X)
End Function
Sub ZBRAC(X1, X2, SUCCES)
    FACTOR = 1.6
    NTRY = 50
    If X1 = X2 Then Print "you have to guess an initial range"
    F1 = FUN(X1)
    F2 = FUN(X2)
    SUCCES = True
    For J = 1 To NTRY
        If F1 * F2 < 0 Then Exit Sub
        If Abs(F1) < Abs(F2) Then
            X1 = X1 + FACTOR * (X1 - X2)
            F1 = FUN(X1)
        Else
            X2 = X2 + FACTOR * (X2 - X1)
            F2 = FUN(X2)
        End If
    Next J
    SUCCES = False
End Sub
Function BESSJ0(X)
    P1# = 1#
    P2# = -0.001098628627
    P3# = 0.00002734510407
    P4# = -0.000002073370639
    P5# = 2.093887211E-07
    Q1# = -0.01562499995
    Q2# = 0.0001430488765
    Q3# = -0.000006911147651
    Q4# = 7.621095161E-07
    Q5# = -9.34945152E-08
    R1# = 57568490574#
    R2# = -13362590354#
    R3# = 651619640.7
    R4# = -11214424.18
    R5# = 77392.33017
    R6# = -184.9052456
    S1# = 57568490411#
    S2# = 1029532985#
    S3# = 9494680.718
    S4# = 59272.64853
    S5# = 267.8532712
    S6# = 1#
    If Abs(X) < 8# Then
       y# = X * X
       BBB# = y# * (R4# + y# * (R5# + y# * R6#))
       AAA# = R1# + y# * (R2# + y# * (R3# + BBB#))
       CCC# = y# * (S3# + y# * (S4# + y# * (S5# + y# * S6#)))
       BESSJ0 = AAA / (S1# + y# * (S2# + CCC#))
    Else
       AX# = Abs(X)
       Z# = 8# / AX#
       y# = Z# * Z#
       XX = AX# - 0.785398164
       CCC# = y# * (P3# + y# * (P4# + y# * P5#))
       AAA# = P1# + y# * (P2# + CCC#)
       DDD# = y# * (Q3# + y# * (Q4# + y# * Q5#))
       EEE# = Z# * Sin(XX) * (Q1# + y# * (Q2# + DDD#))
       BESSJ0 = Sqr(0.636619772 / AX#) * (Cos(XX) * AAA# - EEE#)
    End If
End Function