计算方法实验报告(8)

③ 如果f(a)f(m)<0，则对区间[a,m]调用函数自身（递归），或将m赋值给b（循环），跳转①，

如果f(m)f(b)<0，则对区间[m,b]调用函数自身（递归），或将m赋值给a（循环），跳转①。 （2）牛顿法

xk?1?xk?{//x为初值x0，e为容许误差，返回值为方程的解

f(xk)，x0已知

f'(xk) //每次得到的近似解存入顺序表中，以备后面画图之用

（3）快速弦截法

xk?1?xk?f(xk)xk?xk?1，x0和x1已知

f(xk)?f(xk?1){//x0，x1分别为前两个近似解，用于启动迭代过程，e为容许误差，返回值为方程的解 //将每次迭代结果存入顺序表中，以备后面画图之用 }

也可以定义多个待求解方程为函数，在二分法、牛顿法和弦截法的函数中增加函数指针参数，用以调用不同的待求解方程。

4.4、实验结果

// ThreeDlg.cpp : implementation file //

#include \ #include \ #include \ #include \

#ifdef _DEBUG

#define new DEBUG_NEW #endif

// CAboutDlg dialog used for App About

class CAboutDlg : public CDialogEx { public:

// Dialog Data

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CAboutDlg();

#ifdef AFX_DESIGN_TIME

// Implementation protected: };

CAboutDlg::CAboutDlg() : CDialogEx(IDD_ABOUTBOX) { }

void CAboutDlg::DoDataExchange(CDataExchange* pDX) { }

BEGIN_MESSAGE_MAP(CAboutDlg, CDialogEx) END_MESSAGE_MAP()

// CThreeDlg dialog

CThreeDlg::CThreeDlg(CWnd* pParent /*=NULL*/) { }

double CThreeDlg::fun(double x) { }

double CThreeDlg::dy(double x) { }

return 1 - 2 * cos(x); return x - 2 * sin(x);

m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME); : CDialogEx(IDD_THREE_DIALOG, pParent) CDialogEx::DoDataExchange(pDX); DECLARE_MESSAGE_MAP() protected:

virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support enum { IDD = IDD_ABOUTBOX }; #endif

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int CThreeDlg::parseInt(CString mStr) { }

void CThreeDlg::DoDataExchange(CDataExchange* pDX) { }

BEGIN_MESSAGE_MAP(CThreeDlg, CDialogEx)

// CThreeDlg message handlers

BOOL CThreeDlg::OnInitDialog() {

CMenu* pSysMenu = GetSystemMenu(FALSE); if (pSysMenu != NULL)

// IDM_ABOUTBOX must be in the system command range. ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX); ASSERT(IDM_ABOUTBOX < 0xF000);

// Add \ CDialogEx::OnInitDialog(); ON_WM_SYSCOMMAND() ON_WM_PAINT()

ON_WM_QUERYDRAGICON()

ON_BN_CLICKED(IDC_BUTTON1, &CThreeDlg::OnBnClickedButton1) ON_BN_CLICKED(IDC_BUTTON2, &CThreeDlg::OnBnClickedButton2) ON_BN_CLICKED(IDC_BUTTON3, &CThreeDlg::OnBnClickedButton3) ON_BN_CLICKED(IDC_BUTTON4, &CThreeDlg::OnBnClickedButton4) ON_BN_CLICKED(IDC_BUTTON5, &CThreeDlg::OnBnClickedButton5) ON_BN_CLICKED(IDC_BUTTON6, &CThreeDlg::OnBnClickedButton6) CDialogEx::DoDataExchange(pDX); int x = 0;

for (int i = 0; i < mStr.GetLength(); i++) { } return x;

x *= 10;

x += (mStr.GetAt(i) - '0');

END_MESSAGE_MAP()

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}

{ }

// Set the icon for this dialog. The framework does this automatically // when the application's main window is not a dialog SetIcon(m_hIcon, TRUE);

// Set big icon

SetIcon(m_hIcon, FALSE);

// Set small icon

BOOL bNameValid; CString strAboutMenu;

bNameValid = strAboutMenu.LoadString(IDS_ABOUTBOX); ASSERT(bNameValid);

if (!strAboutMenu.IsEmpty()) { }

pSysMenu->AppendMenu(MF_SEPARATOR);

pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);

// TODO: Add extra initialization here

return TRUE; // return TRUE unless you set the focus to a control

void CThreeDlg::OnSysCommand(UINT nID, LPARAM lParam) { }

// If you add a minimize button to your dialog, you will need the code below // to draw the icon. For MFC applications using the document/view model, // this is automatically done for you by the framework.

void CThreeDlg::OnPaint() {

if (IsIconic()) {

CPaintDC dc(this); // device context for painting if ((nID & 0xFFF0) == IDM_ABOUTBOX) { } else { }

CDialogEx::OnSysCommand(nID, lParam); CAboutDlg dlgAbout; dlgAbout.DoModal();

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}

// The system calls this function to obtain the cursor to display while the user drags // the minimized window.

HCURSOR CThreeDlg::OnQueryDragIcon() { }

void CThreeDlg::OnBnClickedButton1() {

// TODO: 在此添加控件通知处理程序代码 CDC *p = GetDC(); int dl = 30; p->MoveTo(50, 250); p->LineTo(450, 250); p->MoveTo(100, 300); p->LineTo(100, 50 - dl); //绘制箭头 int d = 5;

p->MoveTo(100, 50 - dl);

p->LineTo(100 + d, 50 - dl + d); p->MoveTo(100, 50 - dl);

p->LineTo(100 - d, 50 - dl + d); return static_cast(m_hIcon); } else { }

CDialogEx::OnPaint(); // Draw the icon

dc.DrawIcon(x, y, m_hIcon);

// Center icon in client rectangle int cxIcon = GetSystemMetrics(SM_CXICON); int cyIcon = GetSystemMetrics(SM_CYICON); CRect rect;

GetClientRect(&rect);

int x = (rect.Width() - cxIcon + 1) / 2; int y = (rect.Height() - cyIcon + 1) / 2;

SendMessage(WM_ICONERASEBKGND, reinterpret_cast(dc.GetSafeHdc()), 0);

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