MATLAB编程练习(含答案很好的).doc

001双峰曲线图：z=peaks(40);mesh(z);surf(z)002解方程：A=3,4,-2;6,2,-3;45,5,4; B=14;4;23; root=inv(A)*B003傅里叶变换load mtlb ;subplot(2,1,1);plot(mtlb); title(原始语音信息); y=fft(mtlb); subplot(2,1,2); yy=abs(y); plot(yy); title(傅里叶变换)004输入函数：a=input(How many applesn,s)005输出函数a=1 2 3 4 ;5 6 7 8;12 23 34 45;34 435 23 34a = 1 2 3 4 5 6 7 8 12 23 34 45 34 435 23 34disp(a)a = 1 2 3 4 5 6 7 8 12 23 34 4534 435 23 34b=input(how many peoplen ,s)how many peopletwo peopleb =two people disp(b)two people006求一元二次方程的根a=1;b=2;c=3;d=sqrt(b2-4*a*c);x1=(-b+d)/(2*a)x1 = -1.0000 + 1.4142i x2=(-b-d)/(2*a)x2 = -1.0000 - 1.4142i007求矩阵的相乘、转置、存盘、读入数据A=1 3 5 ;2 4 6;-1 0 -2;-3 0 0; B=-1 3;-2 2;2 1; C=A*BC = 3 14 2 20 -3 -5 3 -9 C=CC = 3 2 -3 3 14 20 -5 -9 save mydat C clear load mydat C008编写数学计算公式：A=2.1;B=-4.5;C=6;D=3.5;E=-5;K=atan(2*pi*A)+E/(2*pi*B*C)/D)K = 1.3121009A=1 0 -1;2 4 1;-2 0 5; B=0 -1 0;2 1 3;1 1 2; H=2*A+BH = 2 -1 -2 6 9 5 -3 1 12 M=A2-3*BM = 3 3 -6 2 13 -2 -15 -3 21 Y=A*BY = -1 -2 -2 9 3 14 5 7 10 R=B*AR = -2 -4 -1 -2 4 14 -1 4 10 E=A.*BE = 0 0 0 4 4 3 -2 0 10 W=ABW = 0.3333 -1.3333 0.6667 0.2500 1.0000 0.2500 0.3333 -0.3333 0.6667 P=A/BP = -2.0000 3.0000 -5.0000 -5.0000 3.0000 -4.0000 7.0000 -9.0000 16.0000 Z=A.BWarning: Divide by zero.Z = 0 -Inf 0 1.0000 0.2500 3.0000 -0.5000 Inf 0.4000 D=A./BWarning: Divide by zero.D = Inf 0 -Inf 1.0000 4.0000 0.3333 -2.0000 0 2.5000010a=4.96;b=8.11; M=exp(a+b)/log10(a+b)M = 4.2507e+005011求三角形面积：a=9.6;b=13.7;c=19.4; s=(a+b+c)/2; area=sqrt(s*(s-a)*(s-b)*(s-c)area = 61.1739012逻辑运算A=-1 0 -6 8;-9 4 0 12.3;0 0 -5.1 -2;0 -23 0 -7; B=A(:,1:2)B = -1 0 -9 4 0 0 0 -23 C=A(1:2,:)C = -1.0000 0 -6.0000 8.0000 -9.0000 4.0000 0 12.3000 D=BD = -1 -9 0 0 0 4 0 -23 A*Bans = 1.0000 -184.0000 -27.0000 -266.9000 0 46.0000 207.0000 69.0000 C C&Dans = 1 0 0 0 0 1 0 1 C|Dans = 1 1 1 1 1 1 0 1 C|Dans = 0 1 1 1 1 0 1 0013矩阵运算练习：A=8 9 5;36 -7 11;21 -8 5A = 8 9 5 36 -7 11 21 -8 5 BB = -1 3 -2 2 0 3 -3 1 9 RT=A*BRT = -5 29 56 -83 119 6 -52 68 -21 QW=A.*BQW = -8 27 -10 72 0 33 -63 -8 45 ER=A3ER = 6272 3342 2944 15714 -856 5260 8142 -1906 2390 BF=A.3BF = 512 729 125 46656 -343 1331 9261 -512 125 A/Bans = 3.1341 4.9634 -0.4024 -1.2561 12.5244 -3.2317 -1.9878 6.4512 -2.0366 EKV=BAEKV = 10.7195 -1.2683 3.5244 9.4756 1.5854 3.7195 4.8537 -1.4878 1.3171 KDK=A,BKDK = 8 9 5 -1 3 -2 36 -7 11 2 0 3 21 -8 5 -3 1 9 ERI=A;BERI = 8 9 5 36 -7 11 21 -8 5 -1 3 -2 2 0 3 -3 1 9014一般函数的调用：A=2 34 88 390 848 939; S=sum(A)S = 2301 min(A)ans = 2 EE=mean(A)EE = 383.5000 QQ=std(A)QQ = 419.3794 AO=sort(A)AO = 2 34 88 390 848 939 yr=norm(A)yr = 1.3273e+003 RT=prod(A)RT = 1.8583e+012 gradient(A)ans = 32.0000 43.0000 178.0000 380.0000 274.5000 91.0000 max(A)ans = 939 median(A)ans = 239 diff(A)ans = 32 54 302 458 91 length(A)ans = 6 sum(A)ans = 2301 cov(A)ans = 1.7588e+005015矩阵变换：A=34 44 23;8 34 23;34 55 2A = 34 44 23 8 34 23 34 55 2 tril(A)ans = 34 0 0 8 34 0 34 55 2 triu(A)ans = 34 44 23 0 34 23 0 0 2 diag(A)ans = 34 34 2norm(A)ans = 94.5106 rank(A)ans = 3 det(A)ans = -23462 trace(A)ans = 70 null(A)ans = Empty matrix: 3-by-0 eig(A)ans = 80.1587 12.7671 -22.9257 poly(A)ans = 1.0e+004 * 0.0001 -0.0070 -0.1107 2.3462 logm(A)Warning: Principal matrix logarithm is not defined for A with nonpositive real eigenvalues. A non-principal matrix logarithm is returned. In funm at 153 In logm at 27ans = 3.1909 + 0.1314i 1.2707 + 0.1437i 0.5011 - 0.2538i 0.4648 + 0.4974i 3.3955 + 0.5438i 0.1504 - 0.9608i 0.2935 - 1.2769i 0.8069 - 1.3960i 3.4768 + 2.4663i fumn(A)? Undefined command/function fumn. inv(A)ans = 0.0510 -0.0502 -0.0098 -0.0326 0.0304 0.0255 0.0305 0.0159 -0.0343 cond(A)ans = 8.5072 chol(A)? Error using = cholMatrix must be positive definite. lu(A)ans = 34.0000 44.0000 23.0000 0.2353 23.6471 17.5882 1.0000 0.4652 -29.1816 pinv(A)ans = 0.0510 -0.0502 -0.0098 -0.0326 0.0304 0.0255 0.0305 0.0159 -0.0343 svd(A)ans = 94.5106 22.3456 11.1095 expm(A)ans = 1.0e+034 * 2.1897 4.3968 1.9382 1.3154 2.6412 1.1643 1.8782 3.7712 1.6625 sqrtm(A)ans = 5.2379 + 0.2003i 3.4795 + 0.2190i 1.8946 - 0.3869i 0.5241 + 0.7581i 5.1429 + 0.8288i 2.0575 - 1.4644i 3.0084 - 1.9461i 4.7123 - 2.1276i 2.1454 + 3.7589i016多项式的计算：A=34 44 23;8 34 23;34 55 2A = 34 44 23 8 34 23 34 55 2 P=poly(A)P = 1.0e+004 * 0.0001 -0.0070 -0.1107 2.3462 PPA=poly2str(P,X)PPA = X3 - 70 X2 - 1107 X + 23462017多项式的运算：p=2 6 8 3;w=32 56 0 2; m=conv(p,w)m = 64 304 592 548 180 16 6 q,r=deconv(w,p)q = 16r = 0 -40 -128 -46 dp=polyder(w)dp = 96 112 0 num,den=polyder(w,p)num = 80 512 724 312 -16den = 4 24 68 108 100 48 9 b=polyfit(p,w,4)Warning: Polynomial is not unique; degree = number of data points. In polyfit at 74b = -0.6704 9.2037 -32.2593 0 98.1333 r=roots(p)r = -1.2119 + 1.0652i -1.2119 - 1.0652i -0.5761 018求多项式的商和余p=conv(1 0 2,conv(1 4,1 1)p = 1 5 6 10 8 q=1 0 1 1q = 1 0 1 1 w,m=deconv(p,q)w = 1 5m = 0 0 5 4 3 cq=w;cr=m; disp(cr,poly2str(m,x) 5 x2 + 4 x + 3 disp(cq,poly2str(w,x) x + 5019将分式分解a=1 5 6;b=1; r,p,k=residue(b,a)r = -1.0000 1.0000p = -3.0000 -2.0000k = 020计算多项式：a=1 2 3;4 5 6;7 8 9; p=3 0 2 3; q=2 3; x=2; r=roots(p)r = 0.3911 + 1.0609i 0.3911 - 1.0609i -0.7822 p1=conv(p,q)p1 = 6 9 4 12 9 p2=poly(a)p2 = 1.0000 -15.0000 -18.0000 -0.0000 p3=polyder(p)p3 = 9 0 2 p4=polyval(p,x)p4 = 31021求除式和余项：q,r=deconv(conv(1 0 2,1 4),1 1 1)022字符串的书写格式：s=students =student name=mary; s1=name s s1 =marystudent s3=name blanks(3);ss3 =mary student023交换两个数：clearclca=1 2 3 4 5;b=6 7 8 9 10;c=a;a=b;b=c;ab24 If语句n=input(enter a number,n=);if nb max=a;else max=b;endmax026三个数按照由大到小的顺序排列：A=15;B=24;C=45;if AB T=A;A=B;B=T;elseif AC T=A;A=C;C=T; elseif BC T=B;B=C;C=T; end A B C027建立一个收费优惠系统：price=input(please jinput the price : price=)switch fix(price/100) case0,1 rate =0; case2,3,4 rate =3/100; case num2cell(5:9) rate=5/100; case num2cell(10:24) rate=8/100; case num2cell(25:49) rate=10/100; otherwise rate=14/100;endprice=price*(1-rate)028：while循环语句i=0;s=0;while i=1212 s=s+i; i=i+1;ends029，用for循环体语句：sum=0;for i=1:1.5:100; sum=sum+i;endsum030循环的嵌套s=0;for i=1:1:6; for j=1:1:8; s=s+ij; end;end;s031continue 语句的使用：for i=100:120; if rem(i,7)=0; continue; end; iend032x=input (输入X的值 x=)if x1&x2 y=x2-1;else y=x2-2*x+1;endy033求阶乘的累加和sum=0;temp=1;for n=1:10; temp=temp*n; sum=sum+temp;endsum034对角线元素之和sum=0;a=1 2 3 4;5 6 7 8;9 10 11 12;13 14 15 16;for i=1:4; sum=sum+a(i,i);endsum035用拟合点绘图A=12 15.3 16 18 25;B=50 80 118 125 150.8;plot(A,B)036绘制正玄曲线：x=0:0.05:4*pi;y=sin(x);plot(x,y)037绘制向量x=1 2 3 4 5 6;7 8 9 10 11 12;13 14 15 16 17 18plot(x)x=0 0.2 0.5 0.7 0.6 0.7 1.2 1.5 1.6 1.9 2.3plot(x)x=0:0.2:2*piy=sin(x)plot(x,y,m:p)038在正弦函数上加标注：t=0:0.05:2*pi;plot(t,sin(t)set(gca,xtick,0 1.4 3.14 56.28)xlabel(t(deg)ylabel(magnitude(v)title(this is a example ()rightarrow 2pi)text(3.14,sin(3.14),leftarrow this zero forpi)039添加线条标注x=0:0.2:12;plot(x,sin(x),-,x,1.5*cos(x),:);legend(First,Second,1)040使用hold on 函数x=0:0.2:12;plot(x,sin(x),-);hold onplot(x,1.5*cos(x),:);041一界面多幅图x=0:0.05:7;y1=sin(x);y2=1.5*cos(x);y3=sin(2*x);y4=5*cos(2*x);subplot(221);plot(x,y1);title(sin(x)subplot(222);plot(x,y2);title(cos(x)subplot(223);plot(x,y3);title(sin(2x)subplot(224);plot(x,y4);title(cos(2x)042染色效果图x=0:0.05:7;y1=sin(x);y2=1.5*cos(x);y3=sin(2*x);y4=5*cos(2*x);subplot(221);plot(x,y1);title(sin(x);fill(x,y1,r)subplot(222);plot(x,y2);title(cos(x);fill(x,y2,b)subplot(223);plot(x,y3);title(sin(2x);fill(x,y3,k)subplot(224);plot(x,y4);title(cos(2x);fill(x,y4,g)043特殊坐标图clcy=0,0.55,2.5,6.1,8.5,12.1,14.6,17,20,22,22.1subplot(221);plot(y);title(线性坐标图);subplot(222);semilogx(y);title(x轴对数坐标图);subplot(223);semilogx(y);title(y轴对数坐标图);subplot(224);loglog(y);title(双对数坐标图)t=0:0.01:2*pi;r=2*cos(2*(t-pi/8);polar(t,r)044特殊函数绘图：fplot(cos(tan(pi*x),-0.4,1.4)fplot(sin(exp(pi*x),-0.4,1.4)045饼形图与条形图：x=8 20 36 24 12;subplot(221);pie(x,1 0 0 0 1);title(饼图);subplot(222);bar(x,group);title(垂直条形图);subplot(223);bar(x,stack);title(累加值为纵坐标的垂直条形图);subplot(224);barh(x,group);title(水平条形图);046梯形图与正弦函数x=0:0.1:10;y=sin(x);subplot(121);stairs(x);subplot(122);stairs(x,y);047概率图x=randn(1,1000);y=-2:0.1:2;hist(x,y)048向量图：x=-2+3j,3+4j,1-7j;subplot(121);compass(x);rea=-2 3 1;imag=3 4 -7;subplot(122);feather(rea,imag);049绘制三维曲线图：z=0:pi/50:10*pi;x=sin(z);y=cos(z);plot3(x,y,z)x=-10:0.5:10;y=-8:0.5:8;x,y=meshgrid(x,y);z=sin(sqrt(x.2+y.2)./sqrt(x.2+y.2);subplot(221);mesh(x,y,z);title(普通一维网格曲面);subplot(222);meshc(x,y,z);title(带等高线的三维网格曲面);subplot(223);meshz(x,y,z);title(带底座的三维网格曲面);subplot(224);surf(x,y,z);title(充填颜色的三维网格面)050 带网格二维图x=0:pi/10:2*pi;y1=sin(x);y2=cos(x);plot(x,y1,r+-,x,y2,k*:)grid onxlabel(Independent Variable x)ylabel(Dependent Variable y1&y2)text(1.5,0.5,cos(x)051各种统计图y=18 5 28 17;24 12 36 14;15 6 30 9;subplot(221);bar(y)x=4,6,8;subplot(222);bar3(x,y)subplot(223);bar(x,y,grouped)subplot(224);bar(x,y,stack)052曲面图x=-2:0.4:2;y=-1:0.2:1;x,y=meshgrid(x,y);z=sqrt(4-x.2/9-y.2/4);surf(x,y,z)grid on053创建符号矩阵e=1 3 5;2 4 6;7 9 11;m=sym(e)符号表达式的计算问题因式分解：syms xf=factor(x3-1)s=sym(sin(a+b);expand(s)syms x tf=x*(x*(x-8)+6)*t;collect(f)syms x f=sin(x)2+cos(x)2;simplify(f)syms xs=(4*x2+8*x+3)/(2*x+1);simplify(s)通分syms x yf=x/y-y/x;m,n=numden(f)嵌套重写syms xf=x4+3*x3-7*x2+12;horner(f)054求极限syms x a;limit(exp(-x),x,0,left)求导数syms x diff(x9+x6)diff(x9+x6,4)055求不定积分与定积分syms x ys=(4-3*x2)2;int(s)int(x/(x+y),x)int(x2/(x+2),x,1,3)double(ans)056函数的变换：syms x ty=exp(-x2);Ft=fourier(y,x,t)fx=ifourier(Ft,t,x)057求解方程syms a b c xs=a*x2+b*x+c;solve(s)syms x y zs1=2*x2+y2-3*z-4;s2=y+z-3;s3=x-2*y-3*z;x,y,z=solve(s1,s2,s3)058求微分方程：y=dsolve(Dy-(t2+y2)/t2/2,t)059求级数和syms x ksymsum(k)symsum(k2-3,0,10)symsum(xk/k,k,1,inf)060泰勒展开式syms xs=(1-x+x2)/(1+x+x2);taylor(s)taylor(s,9)taylor(s,x,12)taylor(s,x,12,5)061练习syms x a;s1=sin(2*x)/sin(5*x);limit(s1,x,0)s2=(1+1/x)(2*x);limit(s2,x,inf)syms xs=x*cos(x);diff(s)diff(s,2)diff(s,12)syms xs1=x4/(1+x2);int(s1)s2=3*x2-x+1int(s2,0,2)syms x y zs1=5*x+6*y+7*z-16;s2=4*x-5*y+z-7;s3=x+y+2*z-2;x,y,z=solve(s1,s2,s3)syms x yy=dsolve(Dy=exp(2*x-y),x)y=dsolve(Dy=exp(2*x-y),y(0)=0,x)n=sym(n);s=symsum(1/n2,n,1,inf)x=sym(x);f=sqrt(1-2*x+x3)-(1-3*x+x2)(1/3);taylor(f,6)062求于矩阵相关的值a=2 2 -1 1;4 3 -1 2;8 5 -3 4;3 3 -2 2adet=det(a)atrace=trace(a)anorm=norm(a)acond=cond(a)arank=rank(a)eiga=eig(a)063矩阵计算A=0.1389 0.6038 0.0153 0.9318;0.2028 0.2772 0.7468 0.4660;0.1987 0.1988 0.4451 0.4186B=var(A)C=std(A)D=range(A)E=cov(A)F=corrcoef(A)064求根及求代数式的值P=4 -3 2 5;x=roots(P)x=3 3.6;F=polyval(P,x)065多项式的和差积商运算：f=1 2 -4 3 -1g=1 0 1g1=0 0 1 0 1f+g1f-g1conv(f,g)q,r=deconv(f,g)polyder(f)066各种插值运算：X=0:0.1:pi/2;Y=sin(X);interp1(X,Y,pi/4)interp1(X,Y,pi/4,nearest)interp1(X,Y,pi/4,spline)interp1(X,Y,pi/4,cubic)067曲线的拟合：X=0:0.1:2*pi;Y=cos(X);p,s=polyfit(X,Y,4)plot(X,Y,K*,X,polyval(p,X),r-)068求函数的最值与0点x=2:0.1:2;x,y=fminbnd(x.3-2*x+1,-1,1)x,y=fzero(x.3-2*x+1,1)069求多项式的表达式、值、及图像y=1 3 5 7 19t=poly(y)x=-4:0.5:8yx=polyval(t,x)plot(x,yx)070数据的拟合与绘图x=0:0.1:2*pi;y=sin(x);p=polyfit(x,y,5);y1=polyval(p,x)plot(x,y,b,x,y1,r)071求代数式的极限：syms xf=sym(log(1+2*x)/sin(3*x);b=limit(f,x,0)072求导数与微分syms xf=sym(x/(cos(x)2);y1=diff(f)y2=int(f,0,1)078划分网格函数x,y=meshgrid(-2:0.01:2,-3:0.01:5);t=x.*exp(-x.2-y.2);px,py=gradient(t,0.05,0.1);td=sqrt(px.2+py.2);subplot(221)imagesc(t)subplot(222)imagesc(td)colormap(gray)079求多次多项方程组的解：syms x1 x2 a ;eq1=sym(x12+x2=a)eq2=sym(x1-a*x2=0)x1 x2=solve(eq1,eq2,x1,x2)v=solve(eq1,eq2)v.x1v.x2an1=x1(1),an2=x1(2)an3=x2(1),an4=x2(2)080求解微分方程：y=dsolve(Dy=-y2+6*y,y(0)=1,x)s=dsolve(Dy=-y2+6*y,y(0)=1,x)u=dsolve(Du=-u2+6*u,u(0)=1)w=dsolve(Du=-u2+6*u,z)u,w=dsolve(Du=-w2+6*w,Dw=sin(z),u(0)=1,w(0)=0,z)v=dsolve(Du=-w2+6*w,Dw=sin(z),u(0)=1,w(0)=0,z)081各种显现隐含函数绘图：f=sym(x2+1)subplot(221)ezplot(f,-2,2)subplot(222)ezplot(y2-x6-1,-2,2,0,10)x=sym(cos(t)y=sym(sin(t)subplot(223)ezplot(x,y)z=sym(t2)subplot(224)ezplot3(x,y,z,0,8*pi)082极坐标图：r=sym(4*sin(3*x)ezpolar(r,0,6*pi)083多函数在一个坐标系内：x=0:0.1:8;y1=sin(x);y2=cos(x);subplot(221)plot(x,y1)subplot(222)plot(x,y1,x,y2)w=2 3;3 1;4 6subplot(223)plot(w)q=4 6:3 5:1 2subplot(224)plot(w,q)084调整刻度图像：x=0:0.1:10;y1=sin(x);y2=exp(x);y3=exp(x).*sin(x);subplot(221)plot(x,y2)subplot(222)loglog(x,y2)subplot(223)plotyy(x,y1,x,y2)085等高线等图形，三维图：t=0:pi/50:10*pi;subplot(2,3,1)plot3(t.*sin(t),t.*cos(t),t.2)grid onx,y=meshgrid(-2:0.1:2)z=x.*exp(-x.2-y.2)subplot(2,3,2)plot3(x,y,z)box offsubplot(2,3,3)meshz(x,y,z)subplot(2,3,4)surf(x,y,z)subplot(2,3,5)contour(x,y,z)subplot(2,3,6)surf(x,y,z)subplot(2,3,5)contour(x,y,z)box offsubplot(2,3,6)contour3(x,y,z)axis off086统计图Y=5 2 1;8 7 3;9 8 6;5 5 5;4 3 2subplot(221)bar(Y)box offsubplot(222)bar3(Y)subplot(223)barh(Y)subplot(224)bar3h(Y)087面积图Y=5 1 2;8 3 7;9 6 8