实验八 数据处理与多项式计算

实验八数据处理与多项式计算1、 (1)a=rand(1,30000);均值：b=mean(a)b=0.4988方差：c=std(a,1,2)c=0.2890(2)最大元素：d=max(a)d=1.0000最小元素：e=min(a)e=4.8345e-05大于0.5的随机数的百分比f=length(find(a>0.5))f=15017p=f/30000p=0.5006sprintf('%f%%',p*100)ans=50.056667%2、 (1)每门课最高分、最低分和学生序号P=round(rand(100,5)*50+45);[a,b]=max(P);a=95 94 95b=27 6 67[c,d]=min(P)c=45 45 46 46d=94 1 34 53(2)每门课平均分和标准方差e=mean(P)e=69.9800 71.5500 69.0〃f=std(P,1,1)9569459170.6700 70.850014.0520 14.6235 13.5543 13.5374 14.9200(3)总分最高分、最低分和学生序号[g,h]=max(sum(P,2))g=441h=6[k,l]=min(sum(F,2))k=272l=19(4)[zcj,xsxh]=sort(sum(P2),'descend')3、h=6:2:18;t1=[18202225302824];t2=[15192428343230];k=6.5:2:17.5;shinei=interp1(h,t1,k,'spline')shiwai=interp1(h,t2,k,'spline')shinei=18.5020 20.4986 22.519326.3775 30.2051 26.817818.5020 20.4986 22.519326.3775 30.2051 26.8178shiwai=15.6553 20.335524.9089 29.638334.2568 30.959415.6553 20.335524.9089 29.638334.2568 30.95944、x=1:10:101;y=[01.04141.32221.49141.61281.70761.78531.85131.90851.95902.0043];p=polyfit(x,y,5);y1=polyval(p,x);plot(x,y1,':o',x,log10(x),'-*')5、(1)p1=[12405];p2=[12];p3=[123];g=conv(p2,p3)g=14 7 6g1=[0,g]；g2=g1+p1g2=1 3 8 7 11a=roots(g2)a=-1.3840+1.8317i-1.3840-1.8317i-0.1160+1.4400i-0.1160-1.4400iA=[-11.2-1.4;0.7523.5;052.5];polyval(g2,A)ans=1.0e+03*0.0100 0.0382 0.01250.0223 0.0970 0.41220.0110 1.2460 0.1644polyvalm(g2,A)ans