1、Matlab 上机实验答案实验一 MATLAB 运算基础1. 先求下列表达式的值，然后显示 MATLAB 工作空间的使用情况并保存全部变量。(1) 012sin85ze z1=2*sin(85*pi/180)/(1+exp(2)z1 =0.2375(2) ，其中221ln()zx210.45ix x=2 1+2i;-0.45 5; z2=1/2*log(x+sqrt(1+x2)z2 =0.7114 - 0.0253i 0.8968 + 0.3658i0.2139 + 0.9343i 1.1541 - 0.0044i(3) 0.3. 0.3sin(.)l,3.0,29,.3022aeaz a=-
2、3.0:0.1:3.0; z3=(exp(0.3.*a)-exp(-0.3.*a)./2.*sin(a+0.3)+log(0.3+a)./2)( z33=(exp(0.3*a)-exp(-0.3*a)/2.*sin(a+0.3)+log(0.3+a)/2)可以验证 z3=z33，是否都为 1）z3 =Columns 1 through 50.7388 + 3.1416i 0.7696 + 3.1416i 0.7871 + 3.1416i 0.7913 + 3.1416i 0.7822 + 3.1416iColumns 6 through 100.7602 + 3.1416i 0.7254 +
3、3.1416i 0.6784 + 3.1416i 0.6196 + 3.1416i 0.5496 + 3.1416iColumns 11 through 150.4688 + 3.1416i 0.3780 + 3.1416i 0.2775 + 3.1416i 0.1680 + 3.1416i 0.0497 + 3.1416iColumns 16 through 20-0.0771 + 3.1416i -0.2124 + 3.1416i -0.3566 + 3.1416i -0.5104 + 3.1416i -0.6752 + 3.1416iColumns 21 through 25-0.853
4、6 + 3.1416i -1.0497 + 3.1416i -1.2701 + 3.1416i -1.5271 + 3.1416i -1.8436 + 3.1416iColumns 26 through 30-2.2727 + 3.1416i -2.9837 + 3.1416i -37.0245 + 0.0000i -3.0017 + 0.0000i -2.3085 + 0.0000iColumns 31 through 35-1.8971 + 0.0000i -1.5978 + 0.0000i -1.3575 + 0.0000i -1.1531 + 0.0000i -0.9723 + 0.0
5、000iColumns 36 through 40-0.8083 + 0.0000i -0.6567 + 0.0000i -0.5151 + 0.0000i -0.3819 + 0.0000i -0.2561 + 0.0000iColumns 41 through 45-0.1374 + 0.0000i -0.0255 + 0.0000i 0.0792 + 0.0000i 0.1766 + 0.0000i 0.2663 + 0.0000iColumns 46 through 500.3478 + 0.0000i 0.4206 + 0.0000i 0.4841 + 0.0000i 0.5379
6、+ 0.0000i 0.5815 + 0.0000iColumns 51 through 550.6145 + 0.0000i 0.6366 + 0.0000i 0.6474 + 0.0000i 0.6470 + 0.0000i 0.6351 + 0.0000iColumns 56 through 600.6119 + 0.0000i 0.5777 + 0.0000i 0.5327 + 0.0000i 0.4774 + 0.0000i 0.4126 + 0.0000iColumn 610.3388 + 0.0000i(4) ，其中 t=0:0.5:2.52401123ttztt t=0:0.5
7、:2.5; z4=(t=034 7 87;3 65 7; B=1 3 -1; 2 0 3;3 -2 7; A+6*Bans =18 52 -1046 7 10521 53 49 I=eye(3); A-B+Ians =12 31 -332 8 840 67 1(2) A*Bans =68 44 62309 -72 596154 -5 241 A.*Bans =12 102 468 0 2619 -130 49(3) A3ans =37226 233824 48604247370 149188 60076678688 454142 118820 A.3ans =1728 39304 -64393
8、04 343 65850327 274625 343(4) A/Bans =16.4000 -13.6000 7.600035.8000 -76.2000 50.200067.0000 -134.0000 68.0000 BAans =109.4000 -131.2000 322.8000-53.0000 85.0000 -171.0000-61.6000 89.8000 -186.2000(5) A,Bans =12 34 -4 1 3 -134 7 87 2 0 33 65 7 3 -2 7 A(1,3,:);B2ans =12 34 -43 65 74 5 111 0 1920 -5 4
9、03. 设有矩阵 A 和 B12345301667891079,2422134513AB(1) 求它们的乘积 C。(2) 将矩阵 C 的右下角 32 子矩阵赋给 D。(3) 查看 MATLAB 工作空间的使用情况。 A=(reshape(1:25,5,5); B=3 0 16;17 -6 9;0 23 -4;9 7 0;4 13 11; C=A*BC =93 150 77258 335 237423 520 397588 705 557753 890 717 D=C(3:5,2:3)D =520 397705 557890 717 whosName Size Bytes Class Attri
10、butesA 5x5 200 double B 5x3 120 double C 5x3 120 double D 3x2 48 double 4. 完成下列操作：(1) 求100,999 之间能被 21整除的数的个数。(2) 建立一个字符串向量，删除其中的大写字母。 n=100:999; l=find(rem(n,21)=0); length(l)ans =43 ch=aegbBOIEG0je23RGnc; wz=find(ch=A R=rand(3,2); O=zeros(2,3); S=diag(1:2); A=E,R;O,SA =1.0000 0 0 0.8147 0.91340 1.0000 0 0.9058 0.63240 0 1.0000 0.1270 0.09750 0 0 1.0000 00 0 0 0 2.0000 A2
