d4r17.frm

来自「常用数值算法集哈」· FRM 代码 · 共 88 行

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   2535
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   3510
   LinkTopic       =   "Form1"
   ScaleHeight     =   2535
   ScaleWidth      =   3510
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   1800
      TabIndex        =   0
      Top             =   1800
      Width           =   1455
   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 D4R17
    'Driver for routine BESSJ1
    Dim ACTUAL(5), X(5)
    ACTUAL(1) = 0.3275791
    ACTUAL(2) = 0.339059
    ACTUAL(3) = -0.3275791
    ACTUAL(4) = 0.0434728
    ACTUAL(5) = -0.0703181
    X(1) = -5#
    X(2) = 3#
    X(3) = 5#
    X(4) = 10#
    X(5) = 13#
    Print
    Print "     X       Actual      BESSJ1(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$(BESSJ1(X(I)), "##.0000000")
    Next I
End Sub
   Function BESSJ1(X)
      R1 = 72362614232#
      R2 = -7895059235#
      R3 = 242396853.1
      R4 = -2972611.439
      R5 = 15704.4826
      R6 = -30.16036606
      S1 = 144725228442#
      S2 = 2300535178#
      S3 = 18583304.74
      S4 = 99447.43394
      S5 = 376.9991397
      S6 = 1#
      P1 = 1#
      P2 = 0.00183105
      P3 = -0.00003516396496
      P4 = 0.000002457520174
      P5 = -0.000000240337019
      Q1 = 0.04687499995
      Q2 = -0.0002002690873
      Q3 = 0.000008449199096
      Q4 = -0.00000088228987
      Q5 = 0.000000105787412
      If Abs(X) < 8# Then
          Y# = X ^ 2
          AAA# = R1 + Y * (R2 + Y * (R3 + Y * (R4 + Y * (R5 + Y * R6))))
          BBB# = S1 + Y * (S2 + Y * (S3 + Y * (S4 + Y * (S5 + Y * S6))))
          BESSJ1 = X * AAA# / BBB#
      Else
          AX = Abs(X)
          Z = 8# / AX
          Y# = Z ^ 2
          XX = AX - 2.356194491
          AAA# = P1 + Y * (P2 + Y * (P3 + Y * (P4 + Y * P5)))
          BBB# = Q1 + Y * (Q2 + Y * (Q3 + Y * (Q4 + Y * Q5)))
          CCC# = Sqr(0.636619772 / AX)
          BESSJ1 = CCC# * (Cos(XX) * AAA# - Z * Sin(XX) * BBB# * Sgn(X))
      End If
   End Function