d4r15.frm

来自「常用数值算法集哈」· FRM 代码 · 共 89 行

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   2715
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   3630
   LinkTopic       =   "Form1"
   ScaleHeight     =   2715
   ScaleWidth      =   3630
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   1800
      TabIndex        =   0
      Top             =   2040
      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 D4R15
    'Driver for routine BESSJ0
    Dim ACTUAL(5), X(5)
    ACTUAL(1) = -0.1775968
    ACTUAL(2) = 1#
    ACTUAL(3) = -0.1775968
    ACTUAL(4) = 0.1716508
    ACTUAL(5) = 0.1710735
    X(1) = -5#
    X(2) = 0#
    X(3) = 5#
    X(4) = 8#
    X(5) = 14#
    Print
    Print "     X      Actual      BESSJ0(X)"
    For I = 1 To 5
        Print Tab(4); Format$(X(I), "#0.0#");
        Print Tab(12); Format$(ACTUAL(I), "##.0000000");
        Print Tab(25); Format$(BESSJ0(X(I)), "##.0000000")
    Next I
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