信息熵统计.cpp

此程序实现了信息熵的实现和统计过程

#include <iostream>
#include <iomanip>
#include <fstream>
#include <math.h>
using namespace std;
void main()
{
	char ch,aa[26],bb[25],cc[2];
	float a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,sum,storet,storer,twostr;
	float dd[26][26];
	int ii,jj;
	a=0;
	b=0;
	c=0;
	d=0;
	e=0;
	f=0;
	g=0;
	h=0;
	i=0;
	j=0;
	k=0;
	l=0;
	m=0;
	n=0;
	o=0;
	p=0;
	q=0;
	r=0;
	s=0;
	t=0;
	u=0;
	v=0;
	w=0;
	x=0;
	y=0;
	z=0;
	sum=0;
	storet=0;
	storer=0;
	twostr=0;
	for(ii=0;ii<=25;ii++)
		for(jj=0;jj<=25;jj++)
		{
			dd[ii][jj]=0;
		}
	for(ii=0;ii<=25;ii++)
	{
		aa[ii]=97+ii;
		bb[ii]=97+ii;
	}
	cc[0]='$';
	cc[1]='$';
	ifstream infile;
	ofstream outfile;
	infile.open("sample.txt");
	outfile.open("result.txt");
	while(infile>>ch)
	{
		switch(ch)
		{
			case 'a':
				{
					a=a+1;
					sum=sum+1;
				}
				break;
			case 'b':
				{
					b=b+1;
					sum=sum+1;
				}
				break;
			case 'c':
				{
					c=c+1;
					sum=sum+1;
				}
				break;
			case 'd':
				{
					d=d+1;
					sum=sum+1;
				}
				break;
			case 'e':
				{
					e=e+1;
					sum=sum+1;
				}
				break;
			case 'f':
				{
					f=f+1;
					sum=sum+1;
				}
				break;
			case 'g':
				{
					g=g+1;
					sum=sum+1;
				}
				break;
			case 'h':
				{
					h=h+1;
					sum=sum+1;
				}
				break;
			case 'i':
				{
					i=i+1;
					sum=sum+1;
				}
				break;
			case 'j':
				{
					j=j+1;
					sum=sum+1;
				}
				break;
			case 'k':
				{
					k=k+1;
					sum=sum+1;
				}
				break;
			case 'l':
				{
					l=l+1;
					sum=sum+1;
				}
				break;
			case 'm':
				{
					m=m+1;
					sum=sum+1;
				}
				break;
			case 'n':
				{
					n=n+1;
					sum=sum+1;
				}
				break;
			case 'o':
				{
					o=o+1;
					sum=sum+1;
				}
				break;
			case 'p':
				{
					p=p+1;
					sum=sum+1;
				}
				break;
			case 'q':
				{
					q=q+1;
					sum=sum+1;
				}
				break;
			case 'r':
				{
					r=r+1;
					sum=sum+1;
				}
				break;
			case 's':
				{
					s=s+1;
					sum=sum+1;
				}
				break;
			case 't':
				{
					t=t+1;
					sum=sum+1;
				}
				break;
			case 'u':
				{
					u=u+1;
					sum=sum+1;
				}
				break;
			case 'v':
				{
					v=v+1;
					sum=sum+1;
				}
				break;
			case 'w':
				{
					w=w+1;
					sum=sum+1;
				}
				break;
			case 'x':
				{
					x=x+1;
					sum=sum+1;
				}
				break;
			case 'y':
				{
					y=y+1;
					sum=sum+1;
				}
				break;
			case 'z':
				{
					z=z+1;
					sum=sum+1;
				}
				break;
			default: break;
		}
		cc[0]=cc[1];
		cc[1]=ch;
		for(ii=0;ii<=25;ii++)
			for(jj=0;jj<=25;jj++)
			{
				if(cc[0]==aa[ii]&&cc[1]==bb[jj])
					dd[ii][jj]=dd[ii][jj]+1;
			}
	}
    storet=(log(26)/log(2))*sum;
	if(a!=0)
	storer=-(a/sum)*((log(a/sum))/(log(2)));
	if(b!=0)
	storer=storer-(b/sum)*((log(b/sum))/(log(2)));
	if(c!=0)
	storer=storer-(c/sum)*((log(c/sum))/(log(2)));
	if(d!=0)
	storer=storer-(d/sum)*((log(d/sum))/(log(2)));
	if(e!=0)
	storer=storer-(e/sum)*((log(e/sum))/(log(2)));
	if(f!=0)
	storer=storer-(f/sum)*((log(f/sum))/(log(2)));
	if(g!=0)
	storer=storer-(g/sum)*((log(g/sum))/(log(2)));
	if(h!=0)
	storer=storer-(h/sum)*((log(h/sum))/(log(2)));
	if(i!=0)
	storer=storer-(i/sum)*((log(i/sum))/(log(2)));
	if(j!=0)
	storer=storer-(j/sum)*((log(j/sum))/(log(2)));
	if(k!=0)
	storer=storer-(k/sum)*((log(k/sum))/(log(2)));
	if(l!=0)
	storer=storer-(l/sum)*((log(l/sum))/(log(2)));
	if(m!=0)
	storer=storer-(m/sum)*((log(m/sum))/(log(2)));
	if(n!=0)
	storer=storer-(n/sum)*((log(n/sum))/(log(2)));
	if(o!=0)
	storer=storer-(o/sum)*((log(o/sum))/(log(2)));
	if(p!=0)
	storer=storer-(p/sum)*((log(p/sum))/(log(2)));
	if(q!=0)
	storer=storer-(q/sum)*((log(q/sum))/(log(2)));
	if(r!=0)
	storer=storer-(r/sum)*((log(r/sum))/(log(2)));
	if(s!=0)
	storer=storer-(s/sum)*((log(s/sum))/(log(2)));
	if(t!=0)
	storer=storer-(t/sum)*((log(t/sum))/(log(2)));
	if(u!=0)
	storer=storer-(u/sum)*((log(u/sum))/(log(2)));
	if(v!=0)
	storer=storer-(v/sum)*((log(v/sum))/(log(2)));
	if(w!=0)
	storer=storer-(w/sum)*((log(w/sum))/(log(2)));
	if(x!=0)
	storer=storer-(x/sum)*((log(x/sum))/(log(2)));
	if(y!=0)
	storer=storer-(y/sum)*((log(y/sum))/(log(2)));
	if(z!=0)
	storer=storer-(z/sum)*((log(z/sum))/(log(2)));
	storer=storer*sum;
	outfile<<"a="<<setw(6)<<a<<"    P(a)="<<a/sum<<endl;
	outfile<<"b="<<setw(6)<<b<<"    P(b)="<<b/sum<<endl;
	outfile<<"c="<<setw(6)<<c<<"    P(c)="<<c/sum<<endl;
	outfile<<"d="<<setw(6)<<d<<"    P(d)="<<d/sum<<endl;
	outfile<<"e="<<setw(6)<<e<<"    P(e)="<<e/sum<<endl;
	outfile<<"f="<<setw(6)<<f<<"    P(f)="<<f/sum<<endl;
	outfile<<"g="<<setw(6)<<g<<"    P(g)="<<g/sum<<endl;
	outfile<<"h="<<setw(6)<<h<<"    P(h)="<<h/sum<<endl;
	outfile<<"i="<<setw(6)<<i<<"    P(i)="<<i/sum<<endl;
	outfile<<"j="<<setw(6)<<j<<"    P(j)="<<j/sum<<endl;
	outfile<<"k="<<setw(6)<<k<<"    P(k)="<<k/sum<<endl;
	outfile<<"l="<<setw(6)<<l<<"    P(l)="<<l/sum<<endl;
	outfile<<"m="<<setw(6)<<m<<"    P(m)="<<m/sum<<endl;
	outfile<<"n="<<setw(6)<<n<<"    P(n)="<<n/sum<<endl;
	outfile<<"o="<<setw(6)<<o<<"    P(o)="<<o/sum<<endl;
	outfile<<"p="<<setw(6)<<p<<"    P(p)="<<p/sum<<endl;
	outfile<<"q="<<setw(6)<<q<<"    P(q)="<<q/sum<<endl;
	outfile<<"r="<<setw(6)<<r<<"    P(r)="<<r/sum<<endl;
	outfile<<"s="<<setw(6)<<s<<"    P(s)="<<s/sum<<endl;
	outfile<<"t="<<setw(6)<<t<<"    P(t)="<<t/sum<<endl;
	outfile<<"u="<<setw(6)<<u<<"    P(u)="<<u/sum<<endl;
	outfile<<"v="<<setw(6)<<v<<"    P(v)="<<v/sum<<endl;
	outfile<<"w="<<setw(6)<<w<<"    P(w)="<<w/sum<<endl;
	outfile<<"x="<<setw(6)<<x<<"    P(x)="<<x/sum<<endl;
	outfile<<"y="<<setw(6)<<y<<"    P(y)="<<y/sum<<endl;
	outfile<<"z="<<setw(6)<<z<<"    P(z)="<<z/sum<<endl;
	outfile<<"sum="<<sum<<endl;
    outfile<<"the theoretical total space of the words is: "<<storet<<" bits"<<endl;
    outfile<<"the practical total space of the words is: "<<storer<<" bits"<<endl;
	for(ii=0;ii<=25;ii++)
		for(jj=0;jj<=25;jj++)
		{
			if(dd[ii][jj]!=0)
				twostr=twostr-(dd[ii][jj]/(sum-1))*((log(dd[ii][jj]/(sum-1)))/(log(2)));
		}
	outfile<<"the two-stair modle of the total space is:"<<twostr*(sum-1)/2<<" bits"<<endl;
	infile.close();
	outfile.close();
}