VB常用数值算法集 内含有解线性代数方程组

				Private Sub Command1_Click()
				    'program D1R9
				    'Driver program for routine SPARSE
				    N = 20
				    Dim B(20), X(20), BCMP(20)
				    '输入已知的方程组的右端向量B
				    For I = 1 To N
				        X(I) = 0#
				        B(I) = 1#
				    Next I
				    B(1) = 3#
				    B(N) = -1#
				    '利用下列子程序ASUB输入已知的方程组的系数矩阵
				    Call SPARSE(B(), N, X(), RSQ)
				    Print
				    Print Tab(5); "Sum - squared residual:", RSQ
				    Print
				    Print Tab(5); "计算出的方程组的解"
				    For I = 1 To 4
				        For J = I * 5 - 4 To I * 5
				            Print Tab((J - (I - 1) * 5) * 9); Format$(X(J), "#.####E+00");
				        Next J
				        Print
				    Next I
				    '将计算出的方程组的解乘以系数矩阵，以验证计算结果正确
				    Call ASUB(X(), BCMP())
				    Print
				    Print Tab(5); "计算出的方程组的解乘以系数矩阵的结果"
				    Print
				    Print Tab(7); "解乘以系数矩阵"; Tab(25); "方程组的右端向量"
				    For I = 1 To N
				        Print Tab(13); Format$(BCMP(I), "##.##"); Tab(32); Format$(B(I), "##.##")
				    Next I
				End Sub
				Sub ASUB(XIN(), XOUT())
				    N = 20
				    XOUT(1) = XIN(1) + 2# * XIN(2)
				    XOUT(N) = -2# * XIN(N - 1) + XIN(N)
				    For I = 2 To N - 1
				        XOUT(I) = -2# * XIN(I - 1) + XIN(I) + 2# * XIN(I + 1)
				    Next I
				End Sub
				Sub ATSUB(XIN(), XOUT())
				    N = 20
				    XOUT(1) = XIN(1) - 2# * XIN(2)
				    XOUT(N) = 2# * XIN(N - 1) + XIN(N)
				    For I = 2 To N - 1
				        XOUT(I) = 2# * XIN(I - 1) + XIN(I) - 2# * XIN(I + 1)
				    Next I
				End Sub