mathview.cpp

计算方法--拉格朗日插值函数

// MathView.cpp : implementation of the CMathView class
//

#include "stdafx.h"
#include "Math.h"

#include "MathDoc.h"
#include "MathView.h"
#include "InputNum.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CMathView

IMPLEMENT_DYNCREATE(CMathView, CView)

BEGIN_MESSAGE_MAP(CMathView, CView)
	//{{AFX_MSG_MAP(CMathView)
	ON_COMMAND(ID_INPUT_NUM, OnInputNum)
	ON_COMMAND(ID_GET_GRAPH, OnOutputGraph)
	ON_WM_MOUSEMOVE()
	ON_COMMAND(ID_SET_COLOR, OnSetColor)
	//}}AFX_MSG_MAP
	// Standard printing commands
	ON_COMMAND(ID_FILE_PRINT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_DIRECT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_PREVIEW, CView::OnFilePrintPreview)
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMathView construction/destruction

CMathView::CMathView()
{
	// TODO: add construction code here
    NodeNum=1;
	m_LineColor=RGB(0,0,0);
}

CMathView::~CMathView()
{
}

BOOL CMathView::PreCreateWindow(CREATESTRUCT& cs)
{
	// TODO: Modify the Window class or styles here by modifying
	//  the CREATESTRUCT cs

	return CView::PreCreateWindow(cs);
}

/////////////////////////////////////////////////////////////////////////////
// CMathView drawing

void CMathView::OnDraw(CDC* pDC)
{
	CMathDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	// TODO: add draw code for native data here
	pDC->MoveTo(50,320);        //绘制坐标轴
	pDC->LineTo(910,320);       //x轴
	pDC->MoveTo(900,315);
	pDC->LineTo(910,320);
	pDC->LineTo(900,326);
	
	pDC->MoveTo(480,480);       //y轴
	pDC->LineTo(480,100);
	pDC->MoveTo(475,110);
	pDC->LineTo(480,100);
	pDC->LineTo(485,110);
	
	double xa=-5.0,ya;
	for(;xa<5.0;xa=xa+0.05)    //原始图像
	{
		ya=1/(1+xa*xa);
		pDC->MoveTo(80*xa+480,320-80*ya);
		ya=1/(1+(xa+0.05)*(xa+0.05));
		pDC->LineTo(80*(xa+0.05)+480,320-80*ya);
	}

    pDC->TextOut(470,322,"0");
    pDC->TextOut(905,325,"x");
    pDC->TextOut(465,100,"y");
}

/////////////////////////////////////////////////////////////////////////////
// CMathView printing

BOOL CMathView::OnPreparePrinting(CPrintInfo* pInfo)
{
	// default preparation
	return DoPreparePrinting(pInfo);
}

void CMathView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add extra initialization before printing
}

void CMathView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add cleanup after printing
}

/////////////////////////////////////////////////////////////////////////////
// CMathView diagnostics

#ifdef _DEBUG
void CMathView::AssertValid() const
{
	CView::AssertValid();
}

void CMathView::Dump(CDumpContext& dc) const
{
	CView::Dump(dc);
}

CMathDoc* CMathView::GetDocument() // non-debug version is inline
{
	ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CMathDoc)));
	return (CMathDoc*)m_pDocument;
}
#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////
// CMathView message handlers

void CMathView::OnInputNum() //输入节点数
{
	// TODO: Add your command handler code here
	CInputNum dNum;
	if(dNum.DoModal()==IDOK)
	{
		NodeNum=dNum.m_nNum;
	}
}

void CMathView::OnOutputGraph() //输出图形
{
	// TODO: Add your command handler code here
	CDC *pDC=GetDC();

	CPen NewPen(PS_DASH,1,m_LineColor);
    CPen *pOldPen=pDC->SelectObject(&NewPen);

	double distance=10.0/NodeNum;
	double t=-5.0;
	for(int i=0;i<NodeNum;i++)    //图像
	{
        x[i]=t;
		y[i]=1/(1+t*t);	
        t=t+distance;
	}
	double wx;

	int n=0;
	for(double xx=-5.0;xx<5.0;xx=xx+0.05) //拉格朗日插值
	{ 
		double ya=0.0;
		for(int k=0;k<NodeNum;k++)
		{	
			double aa=1.0,bb=1.0;
			for (int j=0;j<NodeNum;j++)
			{	

				if(j!=k)
				{  
				   aa*=xx-x[j];
				   bb*=x[k]-x[j];
				}

			}
//			Lx[n] +=y[k]*aa/bb;
			ya +=y[k]*aa/bb;

		}		
//			n++;        
	
		if(xx==-5.0)
			pDC->MoveTo(80*xx+480,320-80*ya);
		else
			pDC->LineTo(80*xx+480,320-80*ya);
			
	}
	
/*    double xxx=-5.0;
	for(int k=0;k<n;k++)
	{
		pDC->MoveTo(80*xxx+480,320-80*Lx[k]);
		xxx +=0.05;
		pDC->LineTo(80*xxx+480,320-80*Lx[k+1]);
	}
*/
	pDC->SelectObject(pOldPen);
//	pDC->ReleaseDC();
}

void CMathView::OnMouseMove(UINT nFlags, CPoint point) 
{
	// TODO: Add your message handler code here and/or call default
	CDC *pDC=GetDC();
	char tbuf[80];
	sprintf(tbuf,"Position:(%3d,%3d)",point.x,point.y);
    pDC->TextOut(20,20,tbuf);
	
	CView::OnMouseMove(nFlags, point);
}

void CMathView::OnSetColor() //设置颜色
{
	// TODO: Add your command handler code here
	CColorDialog dlg;
	if(dlg.DoModal()==IDOK)
	{
	m_LineColor=dlg.GetColor();
	}

}