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1、Matlab程序代码v=-7li=e-,sjsin(75)7J5的函数图象t=0:0.02:10;fl=10sqrt(7.75).*exp(-1.5*t);f2=sin(sqrt(7.75).*t);y=fl.*f2;plot(t,y,-k,t,y,ok);XIabeI(t);ylabel(y(t)%title(函数图像)axis(-210-0.52)Q1拉氏变换clear;clc;symsstfslfs2fs3ftlft2ft3;1.=I,C=0.1,R=1.535;hl=l(1.*C*s2+R(l)*C*s+l);h2=1/(1.*C*s2+R(2)*C*s+1);h3=1/(1.*C*s
2、2+R(3)*C*s+1);fsl=hl*(ls);fs2=h2*(ls);fs3=h3*(ls);ft1=ilaplace(fs1,s,t)；ft2=ilaplacc(fs2,s,t);ft3=ilaplace(fs3,s,t);ezplot(t,ftl);holdon;czplot(t,ft2);holdon;ezplot(t,ft3);xtioiiio100i)进行编码。clear;clc;c=l1011101001fori=l:length(c)ifi=ldl(i)=0;d2(i)=0;elseifi=2dl(i)=c(i-l);d2(i)=c(i-l);elseifi=3d1(i)=
3、mod(c(i-l)+c(i-2),2);d2(i)=c(i-l);elsed1(i)=mod(c(i-l)+c(i-2),2);d2(i)=mod(c(i-l)+c(i-3),2);endenddld2迭代法运用一般迭代法求解方程的3/=，解。第一根：clear;clc;x=IOjerr=I;while(err10-6)Fl=xO;F2=log(3*x02);err=abs(Fl-F2);xO=F2;endx其次根：clear;clc;x=1;err=1;While(err10-6)Fl=x;F2=sqrt(exp(x)/3);err=abs(Fl-F2);x=F2;end第三根：clear
4、;clc;x=10;err=l;while(err10-6)Fl=x;F2=-sqrt(exp(x)3);err=abs(Fl-F2);x=F2;end牛顿迭代法运用牛顿迭代法求解方程-4+3-6=0的解。SymSXfxfx1;fx=2*x3-4*x2+3*x-6;fxl=diff(fx)err=l;k=l;xO=1.5;while(err10A-6&k10A-6&k10-6)&(k10A-6)&(k10-6)&(err210-6)&(err310-6)&(k2,x(2)-cos(x1.egend可加标注。5554.5-.4-，-.35.:.3-.251*t210102030405OG0708
5、091最小二乘拟合functiony=f(x)%f文件定义t=0.250.511.523468;c=(19.2118.1515.3614.1012.989.327.455.243.01;y=c-x(l).*exp(-x(2).*t);clear;clc;%主程序t=0.250.511.523468;c=19.2118.1515.3614.1012.989.327.455.243.01;p,s)=polyfit(t,c,7);%求七阶多项式拟合yl=polyval(p,t);rl=corrcoef(c,yl)x=l2;x)=lsqnonlin(f,x)%最小二乘拟合20.24720.241620
6、.24720.24161.00000.99780.99781.0000y2=x(l).*exp(-x(2).*t);r2=corrcoef(c,y2)v=0:0.01:8;yll=olyval(,v);plot(t,c,ok,v,y11,b,t,y2,r);Iegend(原函数；多项拟合;最小二乘拟合上CommandWindow1.00001.00001.OOOO1.0000OptiJiizationterminated:relativefunctionvaluechangingbylessthanOPTIONS.olFun.最小二乘拟合functiony=fl(x)%定义flt=(0.51.
7、01.52.02.53.011c=1.752.453.814.808.008.60;y=c-x(l).*exp(-x(2).*t);clear;clc;%主程序t=0.51.01.52.02.53.0);c=1.752.453.814.808.008.601;p,s)=polyfit(t,c,7);yl=polyval(p,t);rl=corrcoef(c,y1)x=l2;x=lsqnonlin(f1,x)y=x(l).*exp(-x(2).*t);r2=corrcoef(c,y)v=0.5:0.01:3;yll=polyval(p,v);y2=x(l).*exp(-x(2).*v);lot(
8、t,c,o,v,yll,r,v,y2,g);Iegend(数据？七次多项式拟合？最小二乘拟合);IIrl=1.00001.00001.OOOO1.0000IOptiJiizationterminated:relativefunctionvaluechangingbylessthanOPTIONS.TolFun.1.5124-0.60231.00000.97510.97511.0000线性和非线性规划有约束优化求解函数/5+、=100-犷+(1-疗在约束条件+七*5下及值。xt+x20functionf=f(x)f=100*(x-X2)C2+(1-x)2;functionf1=f(x)U=-(1
9、00*(x-X八2),2+(I-X)人2);clear;clc;x=(l,2;A=l1;-1-1;b三J1.5jO;x=fmincon(f,xO,A,b)f=100*(x(2)-x(1)2).2+(l-x(1)2x=fmincon(,f1,xO,A,b)f=100*(x(2)-x(1)2).2+(l-x(1)2F0.82310.67690.0313-4.27664.27663.30clear;clc;f=-l-3-30001;Aeq=312O10;lO1O21;1O2120;Beq=5;2;6j;1.B=le-6le-6le-6le-6le-6le-6;UB=InfInfInfInfInfIn
10、f;formatlong;x三linprog(f,J,1,Aeq,Beq,1.B,UB)min=-x(1)-3*x(2)-3*x(3)三2o.000001000000064.999993999997310.000001000001215.999994999997310.00000100000011II.99999599999852mm三-14.99998599999560现有三块地，分别为I=100hm2、11=300hm2III=200hm2,须要种植水稻、大豆和玉米，要求最低收获水稻190000kg、大豆130000kg、玉米350000kg,三种作物的但产量如下图所示，市价水稻1.2/k
11、g、大豆Y1.5kg玉米Y08kg。问：1、获得最大产量的种植方案。2、获得最大产值的种植方案。Kghm2IIIIII水稻1100095009000大豆800068006000玉米140001200010000clear;clc;fl=-l100O800014000950068001200090006000100OO;f2=-l1000*1.28000*1.50.8*140001.2*95001.5*68000.8*120001.2*90001.5*60000.8*10000;A=-IllOOOOO9500OO9000O0;08000OO6800OO60000;0O14000OO12000OO
12、100OO;B-190000;130000;350000;Aeq=l11OOOOO0;0OO111OO0;0OOOOO111;Beq=100;300;200;1.B=zeros(9,1);UB=IlOO100100300300300200200200;x,fval=linprog(fl,B,Aeq,Beq,1.B,UB);maxl=-fvalx,fval三linprog(f2,A,B,Aeq,Beq,1.B,UB);max2三-fvalX=1.0e+0020.000000000000050.000000000000120.999999999999830.000000000000060.0000
13、00000000092.999999999999850.211111111111080.216666666666421.57222222222251Yiaxl三6.892222222222176e0061.0e+002，O.58750000000022O.16249999999995O.249999999999832.99999999999975O.00000000000005O.00000000000020I.99999999999997O.00000000000002O.00000000000001max2=6.830499999999992K)O6某产品1900到2010年每个10年的产
14、量为：75.995,91.972,105.711,123.203,131.699,150.696,179.323,203.212,226,505,249,633,256.344,267.893运用差值法求解1995年的产量，井画出相关图像Cclear;clc;x=1900191019201930194019501960197019801990200020101;y=l75.995,91.972,105.711,123.203,131.699,150.696,179.323,203.212,226.505,249.633,256.344,267.893;Y=interpl(x,y,1995,sp
15、line)t=1900:0.1:2010;y1=interp1(x,y,t,spline);plot(t,yl,r,x,y,ok);Iegend值函数,源始数据);2.544042803952399e+0021950到1990年工龄1。、20、30年工作人员劳动酬劳如下:服务年限年份1020301950150.697169.592187.6521960179.323195.072250.2871970203.212239.092322.7671980226.505273.706426.7301990249.633370.281598.243计算1975年时15年工龄的工作人员平均工资。clca
16、r;clc;X=19501960197019801990;19501960197019801990;19501960197019801990;Y=1010101010;2020202020;3030303030;Z=150.697179.323203.212226.505249.633;169.592195.072239.092273.706370.281;187.652250.287322.767426.730598.2431;x=1975;y=15;z=intcrp2(X,Y,Z,x,y,linear)plot3(X,Y,Z)数据如下表，求通过这些点的差值曲面(提示：运用mesh(x,y,
17、z)、SUrf(X,y,z)画图，在其后加Shadinginerp可是曲面光滑)。Y123456112IO11111315216222835272031821263228254202530333220clear;clc;X=l:l:6;Y=(l:1:4),;Z=12IO11111315;162228352720;182126322825;202530333220;x=l:0.01:6;y=(l:0.01:4),;z=interp2(X,Y,Z,x,y,spline);subplot(2,l,l)mcsh(x,y,z);colorbar;subplot(2,l,2)contour(x,y,z);
18、colorbar;matlab求解微分方程解析解:xy-3y,=x2(l)=0,y(5)=0clear;clc;symsxy;y三dsolve(,x*D2y-3*Dy-x2=07y(l)-0,y(5)-0,x,)ezplot(x,y)卜=+4clear;clc;symsxyt;z=dsolve(Dx-x-3*y=0,Dy-x-4=0t)z.xzy(l24!213(l2)exp)exp(-l2(-Hl3(!2)t)Clans三43xp(l2*i2i3fc(l2)t)C24ep(l2-213(l2)t*Clmatlab求解微分方程数值解:乍-(I喏+X=。A-(O)=1.V(O)=Ofunctiondy=f(t,y)dy=zeros(2,l);dy(l)=y(2);dy=2*(l-y人2)*y-y(l);clear;clc;ts=O:0.1:30;T,Y=odel5sff,ts,l,0);plot(T,Y)4
