nprobability.cpp

这是关于飞机生存力计算软件

// NProbability.cpp: implementation of the CNProbability class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "Simulate.h"
#include "NProbability.h"

#include <math.h>

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

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

unsigned long CNProbability::m_ulZ0 = 1;

CNProbability::CNProbability(double dMiu, double dSigema)
{
	m_ulM = 2147483647;
	m_ulA = 16807;
	m_dMiu = dMiu;
	m_dSigema = dSigema;

}

CNProbability::~CNProbability()
{

}

void CNProbability::GetTwoValues(double & dValue1, double & dValue2)
{
	unsigned long ulZ1;
	double dU[2], dV[2], dW, dT, dY, dX[2], dXN[2];
	int i;
 
	while(1)
	{
		for(i = 0; i < 2; i++)
		{
			ulZ1 = m_ulA * m_ulZ0;
			m_ulZ0 = ulZ1 % m_ulM;
			dU[i] = (double)m_ulZ0/(double)m_ulM;
			dV[i] = 2.0 * dU[i] - 1.0;
		}

		dW = dV[0] * dV[0] + dV[1] * dV[1];
		dT = dW - 1.0;
		if(dT > 1.0e-34)
			continue;
		else
			break;
	}
	
	dY = sqrt((-2.0 * log(dW))/dW);

	for(i = 0; i < 2; i++)
	{
	    dX[i] = dV[i] * dY;
	    dXN[i] = m_dMiu + m_dSigema * dX[i];
	}
	dValue1 = dXN[0];
	dValue2 = dXN[1];

}