d2r5.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    =   5295
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   5310
   LinkTopic       =   "Form1"
   ScaleHeight     =   5295
   ScaleWidth      =   5310
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   3720
      TabIndex        =   0
      Top             =   4800
      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 D2R5
    'DRIVER for routine LOCATE
    N = 100
    Dim XX(100)
    'Create array to be searched
    For I = 1 To N
        XX(I) = Exp(I / 20#) - 74#
    Next I
    Print
    Print Tab(5); "Result of:    j=0 indicates x too small"
    Print Tab(5); "              j=100 indicates x too large"
    Print
    Print Tab(5); " locate       j           xx(j)           xx(j+1)"
    'For test
    For I = 1 To 19
        X = -100# + 200# * I / 20#
        Call LOCATE(XX(), N, X, J%)
        If J% = 0 Then
            Print Tab(5); Format$(X, "#0.0000");
            Print Tab(18); Format$(J%, "00");
            Print Tab(28); "lower lim";
            Print Tab(45); Format$(XX(J% + 1), "##.####00")
        ElseIf J% = N Then
            Print Tab(5); Format$(X, "#0.0000");
            Print Tab(18); Format$(J%, "00");
            Print Tab(28); Format$(XX(J%), "##.####00");
            Print Tab(45); "upper lim"
        Else
            Print Tab(5); Format$(X, "#0.0000");
            Print Tab(18); Format$(J%, "00");
            Print Tab(28); Format$(XX(J%), "##.####00");
            Print Tab(45); Format$(XX(J% + 1), "##.####00")
        End If
    Next I
End Sub
Sub LOCATE(XX(), N, X, J%)
    JL = 0
    JU = N + 1
10  If JU - JL > 1 Then
        JM = (JU + JL) / 2
        If XX(N) > XX(1) Eqv X > XX(JM) Then
            JL = JM
        Else
            JU = JM
        End If
        GoTo 10
    End If
    J% = JL
End Sub