d4r30.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    =   5250
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   5205
   LinkTopic       =   "Form1"
   ScaleHeight     =   5250
   ScaleWidth      =   5205
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   3120
      TabIndex        =   0
      Top             =   4320
      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 D4R30
    'Driver for routine ASS
    Open "D:\VB常用数值算法集\DATA\FNCVAL.DAT" For Input As #1
    Do
      Line Input #1, Text$
    Loop While Text$ <> "Exponential Integral Ass"
    Line Input #1, NVAL$
    NVAL = Val(NVAL$)
    Print Text$
    Print
    Print "   N      B       Actual          ASS(N,B)"
    For I = 1 To NVAL
        Line Input #1, DUM$
        N = Val(Mid(DUM$, 1, 7))
        B = Val(Mid(DUM$, 8, 8))
        ACTUAL = Val(Mid(DUM$, 16))
        Print Tab(4); Format$(N, "#0.##");
        Print Tab(10); Format$(B, "#0.##");
        Print Tab(16); Format$(ACTUAL, ".0000000E+00");
        Print Tab(32); Format$(ASS(N, B), ".0000000E+00")
    Next I
    Close #1
End Sub
Function ASS(N, B)
    Dim A(15)
    A(1) = Exp(-B) / B
    If N = 1 Then GoTo 11
    DB = 1# / B
    For I = 2 To N
        A(I) = A(1) + DB * (I - 1) * A(I - 1)
    Next I
11  ASS = A(N)
End Function