d1r12.frm

矩阵特征值的求解过程之二

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   5280
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   4680
   LinkTopic       =   "Form1"
   ScaleHeight     =   5280
   ScaleWidth      =   4680
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   2880
      TabIndex        =   0
      Top             =   4560
      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 D1R12
    'Driver program for routine SSOR
    N = 5
    Dim A(5, 5), B(5), Q(5, 5), C(5, 5), R(5), X(5)
    EPS = 0.00000001
    '松弛因子
    OM = 1.3
    '输入已知的方程组的系数矩阵
    A(1, 1) = 1#: A(1, 2) = 1#: A(1, 3) = 0#: A(1, 4) = 0#: A(1, 5) = 0#
    A(2, 1) = 1#: A(2, 2) = 2#: A(2, 3) = 1#: A(2, 4) = 0#: A(2, 5) = 0#
    A(3, 1) = 0#: A(3, 2) = 1#: A(3, 3) = 3#: A(3, 4) = 1#: A(3, 5) = 0#
    A(4, 1) = 0#: A(4, 2) = 0#: A(4, 3) = 1#: A(4, 4) = 4#: A(4, 5) = 1#
    A(5, 1) = 0#: A(5, 2) = 0#: A(5, 3) = 0#: A(5, 4) = 1#: A(5, 5) = 5#
    '输入已知的方程组的右端向量B
    B(1) = 2#
    B(2) = 4#
    B(3) = 5#
    B(4) = 6#
    B(5) = 6#
    Print
    Print Tab(5); "已知的方程组的右端向量"
    Print Tab(14); Format$(B(1), "##.##")
    Print Tab(14); Format$(B(2), "##.##")
    Print Tab(14); Format$(B(3), "##.##")
    Print Tab(14); Format$(B(4), "##.##")
    Print Tab(14); Format$(B(5), "##.##")
    For I = 1 To N
        For J = 1 To N
           C(I, J) = A(I, J)
        Next J
    Next I
    For I = 1 To N
        R(I) = B(I)
        X(I) = 0#
    Next I
    Call SSOR(C(), N, R(), X(), EPS, OM, II)
    Print
    Print Tab(5); "计算出的方程组的解"
    Print Tab(10); Format$(X(1), "#.####E+00")
    Print Tab(10); Format$(X(2), "#.####E+00")
    Print Tab(10); Format$(X(3), "#.####E+00")
    Print Tab(10); Format$(X(4), "#.####E+00")
    Print Tab(10); Format$(X(5), "#.####E+00")
    '将计算出的解乘以系数矩阵，以验证计算结果正确
    For L = 1 To N
        B(L) = 0#
        For J = 1 To N
            B(L) = B(L) + A(L, J) * X(J)
        Next J
    Next L
    Print
    Print Tab(5); "计算出的解乘以系数矩阵的结果"
    Print Tab(14); Format$(B(1), "##.##")
    Print Tab(14); Format$(B(2), "##.##")
    Print Tab(14); Format$(B(3), "##.##")
    Print Tab(14); Format$(B(4), "##.##")
    Print Tab(14); Format$(B(5), "##.##")
    Print
    Print Tab(5); "迭代次数="; II
End Sub
Sub SSOR(A(), N, B(), X(), EPS, OM, II)
    IMAX = 200
    For I = 1 To N
        R = 1# / A(I, I)
        B(I) = B(I) * R
        For J = 1 To N
            A(I, J) = A(I, J) * R
        Next J
    Next I
    For II = 1 To IMAX
        RX = 0#
        For I = 1 To N
            R = B(I)
            For J = 1 To N
                R = R - A(I, J) * X(J)
            Next J
            If Abs(R) > RX Then RX = Abs(R)
            X(I) = X(I) + OM * R
        Next I
        If OM * RX <= EPS Then Exit Sub
    Next II
    Print "  Too many iterations"
End Sub