nlnewtonrootmainmodule.bas

科学与工程数值计算算法（Visual Basic版） 附赠的光盘包含了本书中全部的源代码

Attribute VB_Name = "MainModule"
Sub Main()
    Dim n As Integer
    Dim x As Double
    
    ' 迭代初值
    x = 1.5
    
    
    '求解
    n = NLNewtonRoot(x, 60, 0.000001)
    
    If n >= 0 Then
        MsgBox "x = " & x
    Else
        MsgBox "求解失败"
    End If
    
End Sub

' 待求解的方程的函数
Sub Func(x As Double, y() As Double)
    y(1) = x * x * x - x * x - 1
    y(2) = 3 * x * x - 2 * x
End Sub