ising model.cpp

一个比较专业的数值计算软件了

#include"iostream.h"
#include"stdlib.h"
#include"math.h"
#include"stdio.h"
#include"string.h"
#include"Box.h"

static long seed1=28;
double rand1()
{	
	long m;
	m=65536;
	seed1=(2053*seed1+13849)%m;
	return double(seed1)/m;
}

void main()
{
	CBox box;
	FILE *fp;
	char dir[]="F:\\my study\\programme\\Ising Modl\\Mvse.txt";
	fp=fopen(dir,"w");
	int numheat=100;
	int num=100;
	int skip=5;
	double J=0;
	double energy;
	int count;
	for(double t=0;t<1.4;t=t+0.01)
	{
		box.SetE(t);
	for(int c=0;c<numheat;c++)
	{
		for(int i=0;i<box.N;i++)
		{
			for(int j=0;j<box.N;j++)
			{
				J=box.CalJ(i,j);
				if(J<=0)//dE<0
				{
					box.Reverseij(i,j);
				}
				else
				{	count=(4-J)/2;
					energy=box.Energy[count];
					if(energy>=rand1())
					{
						box.Reverseij(i,j);
					}
				}
			}
		}
	}
	double M=0;
	double M2=0;
	for(c=0;c<num;c++)
	{
		for(int cc=0;cc<=skip;cc++)
		{
			for(int i=0;i<box.N;i++)
			{
				for(int j=0;j<box.N;j++)
				{
					J=box.CalJ(i,j);
					if(J<=0)//dE<0
					{
						box.Reverseij(i,j);
					}
					else
					{	count=(4-J)/2;
						energy=box.Energy[count];
						if(energy>=rand1())
						{
							box.Reverseij(i,j);
						}
					}
				}
			}
		}
		M=M+box.CalM();
		M2=M2+box.CalM()*box.CalM();
	}
	M=M/(num*box.number);
	M2=M2/(num*box.number*box.number);
	double x=num*box.e*(M2-M*M);
	cout<<"the e is  "<<box.e<<endl;
	cout<<"the M is  "<<M<<endl;
	cout<<"the x is  "<<x<<endl;
	fprintf(fp,"%f,%f,%f\n",box.e,M,x);
	}
}