d3r5.frm

矩阵特征值的求解过程之三

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   4035
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   4680
   LinkTopic       =   "Form1"
   ScaleHeight     =   4035
   ScaleWidth      =   4680
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   3120
      TabIndex        =   0
      Top             =   3360
      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 D3R5
    'Driver for routine MIDPNT
    NMAX = 10
    A = 0#
    B = 1#
    Print
    Print Tab(5); "Integral of FUNC2 computed with MIDPNT"
    Print
    Print Tab(5); "Actual value of integral is";
    Print Tab(35); Format$((FINT2(B) - FINT2(A)), "#.000000")
    Print
    Print Tab(5); "  n    Approx.Integral"
    For I = 1 To NMAX
        Call MIDPNT(A, B, S, I)
        Print Tab(7); Format$(I, "##");
        Print Tab(17); Format$(S, "0.####00")
    Next I
End Sub
Function FUNC2(X)
    FUNC2 = 1# / Sqr(X)
End Function
Function FINT2(X)
    'Integral of FUNC2
    FINT2 = 2# * Sqr(X)
End Function
Sub MIDPNT(A, B, S, N)
    If N = 1 Then
        S = (B - A) * FUNC2(0.5 * (A + B))
        IT = 1
    Else
        IT = 3 ^ (N - 2)
        TNM = IT
        DEL = (B - A) / (3# * TNM)
        DDEL = DEL + DEL
        X = A + 0.5 * DEL
        Sum = 0#
        For J = 1 To IT
            Sum = Sum + FUNC2(X)
            X = X + DDEL
            Sum = Sum + FUNC2(X)
            X = X + DEL
        Next J
        S = (S + (B - A) * Sum / TNM) / 3#
    End If
End Sub