信息与编码实验一

桂林电子科技大学数学与计算科学学院实验报告院(系)数学与计算科学学号1200710218姓名韩尚莉成绩课程名称信息与编码实验实验项目名称实验一信息熵的计算指导教师实验室：06406实验日期：2015年12月12日一，实验目的将一大段英文文章作为要统计的样本文件对样本文件进行一维概率统计，并计算出信源熵及冗余度对样本文件进行二维概率统计，并计算出信源熵及冗余度二，实验原理在进行统计时，首先要在程序中打开文件，然后对文件中的字符读入程序中，进行统计。而在二维统计时，尤其要求对文件的指针操作要熟悉。如读入“newspaper”时，应该依次读入“neewwssppaappeer”，而如果使用fgetc()等命令读文件时，读入的是“newspape”为了依次读入“服ewwssppaappeer”，就要求在每次调入fgetc()等命令后，再将文件指针往后退一步，即要求学生能熟练使用fseek()命令进行指针定位操作。三，使用仪器，材料计算机，VisualC++6.0四，实验内容与步骤(过程及结果截图)首先，下载或者建立一个含有英文字母的txt文档，接下来，编写程序统计字符以及计算熵。一维：#include<stdio.h>#include<string.h>#include<math.h>#define_FILEPATH"F:\\xinhao与编码\\0.txt"#define_ALAPHA_NUMBER((int)('z'-'a'+1))voidPrintStati(intarr[],intsize);intStati(constchar*filePath,intarr[]);floatEntropCompute(intarr[],intsum,intarrSize);intmain(){intarr[_ALAPHA_NUMBER*2]={0};intsampleSize=0;sampleSize=Stati(_FILEPATH,arr);PrintStati(arr,_ALAPHA_NUMBER*2);printf("\n");printf("samplesize:%d\n",sampleSize);printf("entrop:%f\n",EntropCompute(arr,sampleSize,_ALAPHA_NUMBER*2));return0;}voidPrintStati(intarr[],intsize){inti=0;while(i<size){if(i<_ALAPHA_NUMBER){printf("%c:%d",i+'a',arr[i]);}else{printf("%c:%d",i+'A'-_ALAPHA_NUMBER,arr[i]);}i++;}}intStati(constchar*filePath,intarr[]){FILE*pFile=NULL;charc;intsum=0;pFile二fopen(filePath,"rb");if(pFile==NULL){printf("failtoopenfile");return0;}while(1){c=fgetc(pFile);if(c==EOF){break;}if(c>='a'&&c<='z'){arr[c-'a']++;sum++;}elseif(c>='A'&&c<='z'){arr[_ALAPHA_NUMBER+c-'A']++;sum++;}}fclose(pFile);returnsum;}floatEntropCompute(intarr[],intsum,intarrSize){floatentrop=0.0F;inti=0;floatprobability=0;while(i<arrSize){if(arr[i]!=0){probability=(arr[i]*1.0F)/sum;entrop+=(-probability*(log(probability)/log(2)));}i++;}returnentrop;}运彳丁结果：S3F:\xinha曰与编码命名Lexe—OXl：7206b:1818c：2709d:3191e：12962f:1889g：1914h:5286i:7222j:61k:5541:5861Im：2665n：7108o:8408p:2169q：43r:6339s:6658t:10577u：3103v:1223w：1945x:I.33y：2687z：2A:155B:69C:89D:88E:60F:92G:2H:201:309J:66K:2L:1M:79N10:43P:2Q:0R:2S:17T:191U:1V:1W:28X:0Y:2Z:0I;amplesize:105056sntrop:4.240259'rocessexitedwithreturnvalue0'ressanykeytocontinue...二维：#include<stdio.h>#include<math.h>#include<stdlib.h>#defineNULL0intcharge(charc){intn;if(c>=65&&c<=90)c=c+32;if(c>+97&&c<=122){n=c-97;returnn;}elsereturn-1;}intmain(){intcount[26][26]={0};charzifu1,zifu2;inti,n,m,j;intsum=0;floatq,sum1=0;FILE*fp;

if((fp=fopen("F:\\xinhao与编码\\0.txt","rb"))二二NULL){printf("can'topenfile!\n");exit(0);}while(!feof(fp)){zifu1=fgetc(fp);n=charge(zifu1);if(n!=-1){zifu2=fgetc(fp);m=charge(zifu2);if(m!=-1){count[n][m]++;fseek(fp,-1,1);}}}fclose(fp);for(i=0;i<26;i++)for(j=0;j<26;j++)sum=sum+count[i][j];printf("thenumberofallthecodeis%d\n",sum);q=(float)sum;for(i=0;i<26;i++)for(j=0;j<26;j++){if(j%3==0)printf("\n");printf("%c%c,%4d,%6.5f%%",i+97,j+97,count[i][j],count[i][j]*100/q);}printf("\n");for(i=0;i<26;i++)for(j=0;j<26;j++)if(count[i][j]));sum1=sum1+(float)((count[i][j]/q)*log10(1/(double)(count[i][j]/q))/log10((double)(2))printf("\n信息熵为：H(x)=%f\n",sum1);}运彳丁结果：);1>1Z\shang.exeheni_unbero±alltJ^ieoccteis-门ri.rinririri%0.00000%n.nnnnn%u.uuucju%o.00000%u.uuuuu%o.00000%Ij.UUULiij%0.00000%n.nnnnn%o.uuuoo%0.00000%u.UUULJLJ%0.00000%Ij.OOuijij%0.00000%n.nnnnn%u.n.onnnn%U.UUULJLJ%o.00000%ij.UUULuj%0.00000%I-n-r-I--rn-T□n-.■!■-rn-T_Jr-.-I--r-I--r□I-behkn<l七-V工behkn虫t.wubcfhk11aaaaabbbbbbbbbL:c:1---'_■-:-I-n-r-I--rn-T-Jn-Jr-rn-T_Jr-I-I--r-I--r-Jnnonoouo-M-on^.5UO.M-4noo4GSO'J6U4'JJ<L30.□□□□□%0.00000%n.nnnnn%□.uuuuu%0.00000?ou.uuuuu%o.00000%a.oooaawo.00000%n.nnnnnw□.AlLJlb%0.00000%u.uuuuu%0.00000%ij.'joOCuj%0.00033%n.nnnnn%□.uuuuu%口一onnno%U.bya<Lb%0.4SG37%0.01129%0.00000%EF:斶码实验W幅hang’ex巳xp,0,xs,0,Sxy,0,ya,Syd,Syg,Syj,0,ym,59,VP,12,ys,100,yv,0,yy,Sza,0,zd,0,格Sn0,部结结视本ES,本的字入0.00000%0.00000%0.00000%0.00000%0.00000%0.00000%0.00000%0.00000%0.08328%0.01694%0.14115%0.00000%0.00000%0.00000%0.00000%0.00000%0.00000%0.00000%RbK)o%验，将含有中，进行统0.00000%xq,0,xt,17,xw,0,xz,0,yb,0,ye,97,yhn0,yk,0,皿0,双0,yt,1,yw,0,V瓦0,zb,0,ze,1,zh,0,zk,0,zn,0,段英I段英B^实验对zz,0,0.00000%0.02400%0.00000%0.00000%0.00000%0.13691%0.00000%0.00000%0.00000%0.00000%0.00141%0.00000%0.00000%0.00000%0.00141%0.00000%0.00000%0.00000%0.00000%rn作为要统进行一维0.00000%ri.□□□□□%0.00000%n.nnnno%u.uuuuu%0.00000%u.uuuuu%0.00000%u.Ijijuuij%n.nnnnn%u.ouuuo%0.44744%u.0.273S3%0.ij'jOOu%0.45440%n.nnnnn