楼顺天--第二版--matlab7.x-程序设计语言答案(共29页)

1、P83No.3>> A=5-round(100*rand(50,2)/10A = 0.8000 -4.2000 4.1000 5.0000 -1.0000 0.4000 0.3000 0.8000 -2.0000 0.4000 -2.0000 -2.7000 -1.4000 1.8000 4.7000 -2.8000 4.3000 0.3000 1.8000 4.6000 -0.3000 3.2000 -1.5000 -2.2000 0.9000 0.3000 -3.2000 3.5000 -2.2000 1.6000 -4.7000 -1.1000 -0.3000 3.1000

2、1.7000 -2.4000 3.9000 2.6000 -1.1000 -4.2000 -2.8000 2.3000 0.8000 -2.7000 4.1000 3.1000 2.3000 2.1000 3.5000 4.1000 2.2000 -0.8000 0.6000 -1.8000 -0.3000 -0.5000 0.4000 0.7000 -3.8000 -1.4000 -0.2000 -1.5000 -4.4000 -1.8000 -1.4000 -1.4000 -4.6000 -4.5000 2.6000 2.9000 -1.8000 -2.1000 2.1000 2.6000

3、 -1.7000 3.8000 -2.0000 -1.1000 4.3000 0.5000 2.5000 0.4000 2.8000 -1.6000 -1.7000 -2.7000 -3.4000 1.5000 1.6000 -1.6000 -2.8000 0.8000 -1.8000 -3.4000 4.9000 -3.3000 -1.0000 2.40001.1000 -1.1000No.6>> A=randn(10,10)A = -0.4326 -0.1867 0.2944 -0.3999 -1.6041 -1.0106 0.0000 0.5689 0.6232 0.3899

4、 -1.6656 0.7258 -1.3362 0.6900 0.2573 0.6145 -0.3179 -0.2556 0.7990 0.0880 0.1253 -0.5883 0.7143 0.8156 -1.0565 0.5077 1.0950 -0.3775 0.9409 -0.6355 0.2877 2.1832 1.6236 0.7119 1.4151 1.6924 -1.8740 -0.2959 -0.9921 -0.5596 -1.1465 -0.1364 -0.6918 1.2902 -0.8051 0.5913 0.4282 -1.4751 0.2120 0.4437 1.

5、1909 0.1139 0.8580 0.6686 0.5287 -0.6436 0.8956 -0.2340 0.2379 -0.9499 1.1892 1.0668 1.2540 1.1908 0.2193 0.3803 0.7310 0.1184 -1.0078 0.7812 -0.0376 0.0593 -1.5937 -1.2025 -0.9219 -1.0091 0.5779 0.3148 -0.7420 0.5690 0.3273 -0.0956 -1.4410 -0.0198 -2.1707 -0.0195 0.0403 1.4435 1.0823 -0.8217 0.1746

6、 -0.8323 0.5711 -0.1567 -0.0592 -0.0482 0.6771 -0.3510 -0.1315 -0.2656>> i,j=find(-0.5<A<0.5)i = 2 5 3 10 2 5 8 9 8 1 3 5 8 9 1 6 8 4 5 4 7 8 3 4 6 9j = 1 1 2 2 3 3 3 3 4 5 5 5 5 5 6 6 6 7 8 9 9 9 10 10 10 10>> length(j)ans = 26P146No.5clear;x=-3:0.1:3;figure(1)y1=2*x+5;y2=x.2-3*x+

7、1;subplot(1,2,1),plot(x,y1),title('函数1')axis(-3 3 -5 5)subplot(1,2,2),plot(x,y2),title('函数2')axis(-3 3 -5 5)No.7clear;x=190 33 45 42 45;h=pie(x,'生活费','资料费','电话费','购买衣服','其他费用')explode=0 1 0 0 0;figure(1)pie(x,'生活费','资料费','电话

8、费','购买衣服','其他费用')title('每月消费比例')h = 175.0033 176.0023 177.0022 178.0022 179.0022 180.0022 181.0022 182.0022 183.0022 184.0022No.9x,y=meshgrid(-2:0.25:2);>> z=x.2+y.2+sin(x*y);>> contour3(x,y,z,30)surface(x,y,z,'EdgeColor',.8 .8 .8,'FaceColor',&

9、#39;none')>> grid off>> view(-15,25)P184No.1clear;function t=sushu(n)n=input(输入的数是)A=sqrt(n);k=floor(A);for i=2:kif mod(n,i)=0 t=0; break;else t=1;endendNo.3zeros_num_all = 0;for i=1:2006 zeros_num = zeroscnt1(i); %zeros_num = zeroscnt2(i); zeros_num_all = zeros_num + zeros_num_all;e

10、nddisp('12006中“0”的个数为：',num2str(zeros_num_all)zeroscnt1函数：function num = zeroscnt1(data)data_str = num2str(data);num_vec = find(data_str = '0');num = length(num_vec);zeroscnt2函数function num = zeroscnt2(data)num = 0;while(data>=1) if mod(data,10) = 0 num = num + 1; data = fix(data/

11、10); else data = fix(data/10); endendNo.5i=0;for x=-3:0.01:3 i=i+1; X(i)=x; if and(x>=-3,x<-1) Y(i)=(-x*x-4*x-3)/2; elseif and(x>=-1,x<1) Y(i)=-x*x+1; else Y(i)=(-x*x+4*x-3)/2; endendplot(X,Y)No.8clear;I=input(个人完成的利润为)if I<=10 y=I*0.1 elseif I>10&I<=20 y=10*10+(I-10)*0.05 e

12、lseif I>20&I<=40 y=10*0.15+(I-20)*0.02 elseif I>40 y=10*0.17+(I-40)*0.01 end>> m02个人完成的利润为25I = 25y = 1.6000No.9clear;i=1;s=0;a1=1;a2=1;while i<16 k=a1; a1=a1+a2; a2=k; s=s+a1/a2; i=i+1;end>> ss = 24.5701P263No.1(1) >>a=1 9 8;7 2 5;3 -2 7a = 1 9 8 7 2 5 3 -2 7>&g

13、t; det(a)ans = -442>> inv(a)ans = -0.0543 0.1787 -0.0656 0.0769 0.0385 -0.1154 0.0452 -0.0656 0.1380(2) >> b=1 0 -7 5;0 -26 7 2;7 4 3 5;8 -3 2 15b = 1 0 -7 5 0 -26 7 2 7 4 3 5 8 -3 2 15>> det(b)ans = -9334>> inv(b)ans = 0.1501 0.0654 0.3046 -0.1603 -0.0509 -0.0471 -0.0312 0.0

14、336 -0.1697 -0.0204 -0.0703 0.0827 -0.0676 -0.0416 -0.1593 0.1478No.22,（1）>> a1=1 2 3;2 2 5;3 5 1;>> b1=11;12;31;x1=inv(a1)*b1x1 = 1.8000 5.2000 -0.4000（2）a2=3 1 0 5;0 6 7 3;0 4 3 0;2 -1 2 6;b2=2;4;7;8;>> x2=inv(a2)*b2x2 = 28.1892 -9.4595 14.9459 -14.6216No.3clear;t=1:1:10;t=t'

15、y=4.842,4.362,3.754,3.368,3.169,3.083,3.304,3.016,3.012,3.005'x1=ones(size(t),exp(-t);x2=ones(size(t),t.*exp(-t);p1=x1y;p2=x2y;tt=linspace(1,10,1000);plot(t,y,'*',tt,p1(1)+p1(2)*exp(-tt),'r-',tt,p2(1)+p2(2)*tt.*exp(-tt),'c-')grid on,legend('给定数据','y1拟合',&#

16、39;y2拟合')No.7clear;t=1:10;tt=1:0.01:10;y=15,39.5,66,85.5,89,67.5,12,-86.4,-236.9,-448.4;p1=polyfit(t,y,2);y1=polyval(p1,tt);p2=polyfit(t,y,3);y2=polyval(p2,tt);plot(t,y,'b*',tt,y1,'r-',tt,y2,'c-');legend('样本点','二次拟合','三次拟合'),grid onNo.8p1,p2,p3,p4p

17、1 = 1 -2 -3 4 2p2 = 1 -7 5 31 -30p3 = 1 -1 -25 25p4 = -2 3 1 5 8 0>> roots(p1),roots(p2),roots(p3),roots(p4)ans = 2.4142 1.4142 -1.4142 -0.4142ans = 5.0000 -2.0000 3.0000 1.0000ans = -5.0000 5.0000 1.0000ans = 0 2.4176 0.0148 + 1.3215i 0.0148 - 1.3215i -0.9473 No.9y11=polyval(p1,-1.5),y12=poly

18、val(p1,2.1),y13=polyval(p1,3.5)y11 = 1.0625y12 = -1.9039y13 = 43.5625>> y21=polyval(p2,-1.5),y22=polyval(p2,2.1),y23=polyval(p2,3.5)y21 = -36.5625y22 = 11.7711y23 = -10.3125>> y31=polyval(p3,-1.5),y32=polyval(p3,2.1),y33=polyval(p3,3.5)y31 = 56.8750y32 = -22.6490y33 = -31.8750>> y4

19、1=polyval(p4,-1.5),y42=polyval(p4,2.1),y43=polyval(p4,3.5)y41 = 26.2500y42 = 24.7733y43 = -468.1250 13, 15,16,20No.13>> a=rand(1,50);amax=max(a)amin=min(a)ua=mean(a)vara=(std(a)2b=randn(1,50);bmax=max(a)bmin=min(a)ub=mean(a)varb=(std(a)2amax = 0.9706amin = 0.0318ua = 0.5661vara = 0.0977bmax =

20、0.9706bmin = 0.0318ub = 0.5661varb = 0.0977No.15>> t=0:1/199:1;>> x=3*sin(2*pi*20*t)+10*sin(2*pi*200*t+0.25*pi)+10*randn(size(t);>> y=fft(x);>> m=abs(y);>> f=(0:length(y)-1)'*199/length(y);>> figure(1)>> subplot(2,1,1),plot(t,x),grid on>> title(

21、9;信号检测')>> ylabel('Inputitx'),xlabel('Time')>> subplot(2,1,2),plot(f,m)>> ylabel('Abs.Magnitude'),grid on>> xlabel('Frequency(Hertz)')No.16w=1;t=0:pi/50:2*pi;x1=sin(w*t)+randn(size(t);x2=cos(w*t)+randn(size(t);x3=sin(w*t)+randn(size(t);R1=c

22、orrcoef(x1,x2)R2=corrcoef(x1,x3)y1=randn(size(t);y2=randn(size(t);y3=randn(size(t);Q1=corrcoef(y1,y2)Q2=corrcoef(y1,y3)R1 = 1.0000 0.0420 0.0420 1.0000R2 = 1.0000 0.2641 0.2641 1.0000Q1 = 1.0000 -0.0791 -0.0791 1.0000Q2 = 1.0000 0.0254 0.0254 1.0000No.20M函数：function dy=diffequat1(t,y)dy=0.5-y(1);y(1

23、)-4*y(2);Matble：>> X0=1;-0.5;>> tspan=0,50;>> clear all>> X0=1;-0.5;>> tspan=0,25;>> T,X=ode45('diffequat1',tspan,X0);>> figure(1)>> subplot(2,1,1),plot(T,X(:,1),'r'),title('x_1'),grid on>> subplot(2,1,2),plot(T,X(:,2),

24、9;k'),title('x_2'),grid on>> figure(2)>> plot(X(:,1),X(:,2),title('系统轨迹'),grid on>> xlabel('x_1'),ylabel('x_2')P313No.2A=65 76 78 87 76;64 78 67 87 95;64 65 78 88 76;78 90 81 83 85;67 89 87 78 86;69 74 78 81 82;A(:,:,2)=67 87 67 78 65;65 76 87 67

25、 59;78 90 67 87 86;74 67 87 67 87;89 67 87 87 86;80 80 81 82 84;A(:,:,3)=67 80 82 85 87;87 87 87 87 87;85 75 65 75 75;80 89 89 89 89;79 79 79 79 79;90 90 67 78 90;A(:,:,4)=78 78 78 78 78;67 89 76 87 82;78 56 76 87 67;90 92 89 87 86;78 89 78 67 89;91 90 85 85 86;A(:,:,5)=68 87 86 86 86;78 90 76 76 78

26、;78 98 78 76 87;78 97 87 67 75;78 90 65 76 89;67 87 78 87 78;A(:,:,6)=87 87 87 87 78;78 87 90 78 76;75 78 76 75 74;76 87 85 86 88;88 77 90 87 89;85 87 88 90 83;A(:,:,7)=68 87 85 84 80;88 80 89 85 90;78 79 70 79 88;88 78 91 88 80;69 87 86 85 83;80 88 78 78 87;A(:,:,8)=67 80 82 85 87;87 87 87 88 87;85

27、 79 65 75 75;80 89 89 89 89;79 79 79 79 79;90 90 67 78 90;A(:,:,9)=67 87 67 78 65;65 76 88 67 59;78 90 67 87 86;74 67 87 67 87;80 67 87 87 86;80 80 81 82 84;A(:,:,10)=87 78 78 78 78;67 89 76 87 82;78 56 76 87 67;90 90 89 87 86;78 89 78 67 89;91 90 85 85 86;gra=Afor i=1:length(gra) mean_gra=mean(mean

28、(gra(6,5,i); a(i,1)=mean_gra; disp(num2str(i) '宿舍平均分是' num2str(mean_gra);endsit=sort(a);disp('排名如下')for i=1:10 disp('第' num2str(11-i) '名分数是' num2str(sit(i,1);end结果：gra(:,:,1) = 65 76 78 87 76 64 78 67 87 95 64 65 78 88 76 78 90 81 83 85 67 89 87 78 86 69 74 78 81 82gr

29、a(:,:,2) = 67 87 67 78 65 65 76 87 67 59 78 90 67 87 86 74 67 87 67 87 89 67 87 87 86 80 80 81 82 84gra(:,:,3) = 67 80 82 85 87 87 87 87 87 87 85 75 65 75 75 80 89 89 89 89 79 79 79 79 79 90 90 67 78 90gra(:,:,4) = 78 78 78 78 78 67 89 76 87 82 78 56 76 87 67 90 92 89 87 86 78 89 78 67 89 91 90 85 8

30、5 86gra(:,:,5) = 68 87 86 86 86 78 90 76 76 78 78 98 78 76 87 78 97 87 67 75 78 90 65 76 89 67 87 78 87 78gra(:,:,6) = 87 87 87 87 78 78 87 90 78 76 75 78 76 75 74 76 87 85 86 88 88 77 90 87 89 85 87 88 90 83gra(:,:,7) = 68 87 85 84 80 88 80 89 85 90 78 79 70 79 88 88 78 91 88 80 69 87 86 85 83 80 8

31、8 78 78 87gra(:,:,8) = 67 80 82 85 87 87 87 87 88 87 85 79 65 75 75 80 89 89 89 89 79 79 79 79 79 90 90 67 78 90gra(:,:,9) = 67 87 67 78 65 65 76 88 67 59 78 90 67 87 86 74 67 87 67 87 80 67 87 87 86 80 80 81 82 84gra(:,:,10) = 87 78 78 78 78 67 89 76 87 82 78 56 76 87 67 90 90 89 87 86 78 89 78 67

32、89 91 90 85 85 861宿舍平均分是822宿舍平均分是843宿舍平均分是904宿舍平均分是865宿舍平均分是786宿舍平均分是837宿舍平均分是878宿舍平均分是909宿舍平均分是8410宿舍平均分是86排名如下第10名分数是78第9名分数是82第8名分数是83第7名分数是84第6名分数是84第5名分数是86第4名分数是86第3名分数是87第2名分数是90第1名分数是903. ='jack'infor.bdate='oct 1st'infor.adress='USA'infor.phnum='3888888

33、'infor.emil='hao'='math'course.teacher='wang Fei'course.time=20;course.score=6;course(2).name='English'course(2).teacher='Li Fei'course(2).time=20;course(2).score=6;course(3).name='biology'course(3).teacher='wang Lei'course(3).ti

34、me=20;course(3).score=6;pition='math'='no'TS1='math',1 2 3 4,76 68 70 71;TS2='English',1 2 3 4,70 80 85 90;TS3='biology',1 2 3 4,88 89 90 91;TS=cat(3,TS1,TS2,TS3);s=0;v=0; for i=1:4 for j=1:3 s1=course(j).score; v1=TS1,3,j(1,i); s=s+s1; v=v+v1*s1; end

35、 ave=v/s; disp('第' num2str(i) '学期加权平均分是' num2str(ave) end第1学期加权平均分是78第2学期加权平均分是78.5第3学期加权平均分是79.5556第4学期加权平均分是80.6667P344No.3x=-1:.001:1;y1=fun(x);y2=fun1(x);figure(1)plot(x,y1,'r-',x,y2,'b-')grid onxlabel('x'),ylabel('y');y2_max_val,y2_max_ind = max(y

36、1);y2_max_t = x(y2_max_ind);text(y2_max_t,y2_max_val,'rightarrow(', num2str(y2_max_t),',',num2str(y2_max_val),')')x1=fminbnd('fun1',-0.6,0);a1=fun1(x1);text(x1,a1,'rightarrow (', num2str(x1),',',num2str(a1),')')x2=fminbnd('fun1',0.6,1);

37、a2=fun1(x2);text(x2,a2,'rightarrow (', num2str(x2),',',num2str(a2),')')x3=fminbnd('fun2',-0.8,-0.4);a3=fun1(x3);text(x3,a3,'rightarrow (', num2str(x3),',',num2str(a3),')')x4=fminbnd('fun2',0,0.4);a4=fun1(x4);text(x4,a4,'rightarrow (

38、', num2str(x4),',',num2str(a4),')')fun函数function y=fun(x)y = -2*x.2+4;结果：No.4clear allclose allsen='we','will','rock','you'as=double('Iamastudent');for i=1:4 name(1,i)=sen(1,i) no(1,i)=i Length(1,i)=length(cell2mat(sen(1,i) value(1,i)=sum(a

39、s(1,i:i-1+Length(1,i)ends=struct('name',name,'no',num2cell(no),'length',num2cell(Length),'value',num2cell(value)name = 'we'no = 1Length = 2value = 170name = 'we' 'will'no = 1 2Length = 2 4value = 170 418name = 'we' 'will' 'r

40、ock'no = 1 2 3Length = 2 4 4value = 170 418 437name = 'we' 'will' 'rock' 'you'no = 1 2 3 4Length = 2 4 4 3value = 170 418 437 328s = 1x4 struct array with fields: name no lengthvalueMATLAB综合作业a=input('姓名：','s');b=input('月份：');c=input('日

41、期：');d=input('颜色：(蓝色、红色、黄色、绿色中选取）','s');switch b case 1 disp('小寒 01月06日 06:43:54 大寒 01月21日 00:09:49') case 2 disp('立春 02月04日 18:22:23 雨水 02月19日 14:17:35 ') case 3 disp('惊蛰 03月05日 12:21:02 春分 03月20日 13:14:25 ') case 4 disp('清明 04月04日 17:05:36 谷雨 04月20日

42、00:12:04 ') case 5 disp('立夏 05月05日 10:19:40 小满 05月20日 23:15:31') case 6 disp('芒种 06月05日 14:25:53 夏至 06月21日 07:08:48') case 7 disp('小暑 07月07日 00:40:43 大暑 07月22日 18:00:51') case 8 disp('立秋 08月07日 10:30:32 处暑 08月23日 01:06:50') case 9 disp('白露 09月07日 13:29:00 秋分 09月22日 22:48:59') case 10 disp('寒露 10月08日 05:11:42 霜降 10月23日 08:13:33') case 11 disp('立冬 11月07日 08:25:56 小雪 11