stcs.h

一个模拟沃尔玛柜台结账的排队论仿真

#ifndef STCS_H
#define STCS_H

#include <iostream.h>
#include <math.h>
#include "sev.h"
#include "link.h"
#include "gen.h"

double mean(double n, double av,double x){	return (av*(n-1)+x)/n;}
double var(double n, double s, double m, double x)
{
	if(n<2)
		return 1;
	return s*(n-2)/(n-1)+n*(x-m)*(x-m)/(n-1)/(n-1);
}

class Stcs
{
public:
	
	Stcs(list<Event>* q,Sev* s);
	void calStcs(int type,double tim);
	void calAD(int type,double tim);	
	friend	ostream& operator<<(ostream& out,Stcs& st);
	
	list<Event>* que;
	Sev* sev;

public:
	double num;	//jobs in system, n=nq+ns
	double nq;	//jobs in queue
	double ns;	//jobs in servers
	double rsp;	//response time r=w+s
	double w;	//waiting time
	double s;	//service time per job
	double n;

	double mnq;
	double varNq;
	double varNs;

	double nLda;
	double nMu;
	double avrLda;	
	double avrMu;
};

Stcs::Stcs(list<Event>* q,Sev* s):num(0),nq(0),ns(0),rsp(0),w(0),s(0),n(0),varNq(0),varNs(1)
{
	nLda=0;		nMu=0;
	avrLda=0;	avrMu=0;
	mnq=0;
	que=q;
	sev=s;
}


void Stcs::calStcs(int type,double tim)
{
	n++;

	assert(que);
	assert(sev);	
	
	double lq=que->getLen();
	double ls=sev->getSta();

	if(n>STA_POINT)
	{
		nq=mean(n,nq,lq);
		ns=mean(n,ns,ls);	
		num=nq+ns;

		mnq=mean(n,mnq,nq);
		varNq=var(n-STA_POINT,varNq,mnq,nq);
///////////////response time/////////////////////////////////////////////
		if(type>=0 && sev->getSta()==1)
		{
			double lw=sev->evt->getInqStp()-sev->evt->getStrStp();
			double ls=sev->evt->getEndStp()-sev->evt->getInqStp();
			
			w=mean(n,w,lw);
			s=mean(n,s,ls);
			rsp=w+s;
		}
////////////////////////////////////////////////////////////////////////
	}

	calAD(type,tim);
}

void Stcs::calAD(int type,double tim)
{
	if(type==GEN)
	{		
		nLda++;
		avrLda=nLda/tim;		
	}
	else
	{
		if(sev->getSta()==1)
		{
			nMu++;
			avrMu=nMu/tim;			
		}
	}	
}

ostream& operator<<(ostream& out,Stcs& st)
{	out<<"Total jobs: "<<st.n<<" | "
		<<"Mean jobs in sys: "<<st.num<<" | "
		<<"Mean response time: "<<st.rsp<<" | ";	
	return out;
}

#endif