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1、1.频数表和直方图：统计100名同学的身高和体重直方图身高体重身高体重身高体重身高体重身高体重172751695516964171651674717162168671655216962168651666216865164591705816564160551756717374172641685715557176641726916958176571735816850169521677217057166551614917357175761585117063169631736116459165621675317161166701666317253173601786416357169541696617
2、86017766170561675416958173731705816065179621725016347173671655817663162521656617259177661826917575170601706216963186771746616350172591766016676167631725717758177671697216650182631766817256173591746417159175681655616965168621776418470166491717117059先把数据写入一个纯文本数据文件data.txt中，数据列之间用空格键或Tab键分割，该数据文件data
3、.txt存放在matlabwork子目录下，在Matlab中用load命令读入数据，具体作法是：loaddata.txtloaddata.txt;high=data(:,1:2:9);high=high(:);weight=data(:,2:2:10);weight=weight(:);[n1,x1]=hist(high)%下面语句与hist命令等价%n1=[length(find(high<158.1)),...%length(find(high>=158.1&high<161.2)),...%length(find(high>=161.2&high<164.5)),...%length
4、(find(high>=164.5&high<167.6)),...%length(find(high>=167.6&high<170.7)),...%length(find(high>=170.7&high<173.8)),...%length(find(high>=173.8&high<176.9)),...%length(find(high>=176.9&high<180)),...%length(find(high>=180&high<183.1)),...%length(find(high>=183.1))][n2,x2]=hist(weight)subplot(1,2,1),hi
5、st(high)subplot(1,2,2),hist(weight)2.统计下列五行字符串中字符a、g、c、t出现的频数：1.aggcacggaaaaacgggaataacggaggaggacttggcacggcattacacggagg2.cggaggacaaacgggatggcggtattggaggtggcggactgttcgggga3.gggacggatacggattctggccacggacggaaaggaggacacggcggacataca4.atggataacggaaacaaaccagacaaacttcggtagaaatacagaagctta5.cggctggcggacaacgga
6、ctggcggattccaaaaacggaggaggcggacggaggc把上述五行复制到一个纯文本数据文件shuju.txt中，放在matlabwork子目录下，编写如下程序：clcfid1=fopen('shuju.txt','r');i=1;while(~feof(fid1))data=fgetl(fid1);a=length(find(data==97));b=length(find(data==99));c=length(find(data==103));d=length(find(data==116));e=length(find(data>=97&data<=122));f(
7、i,:)=[abcdea+b+c+d];i=i+1;endf,he=sum(f)dlmwrite('pinshu.txt',f);dlmwrite('pinshu.txt',he,'-append');fclose(fid1);我们把统计结果最后写到一个纯文本文件pinshu.txt中，在程序中多引进了几个变量，是为了检验字符串是否只包含a、g、c、t四个字符。
