丁丽娟《数值计算方法》五章课后实验题答案(源程序很详细,且运行无误).docx
丁丽娟数值计算方法五章课后实验题答案(源程序都是自己写的，很详细，且保证运行无误)我做的五章数值实验作业题目如下：第二章：1、2、3、4题第三章：1、2题第四章：1、2题第六章：2、3题第八章：1、2题第二章(D对A进行列主元素三角分解：function1u=myfun（八）n=size（八）;fork=l:nfori=k:nsum=0;m=k;forj=k(k-l)sum=sum+A(i,j)*A(j,k);ends(i)=A(i,k)-sum;ifabs(s(m)<abs(s(i)m=i;endendforj=knc=A(m,j);A(m,j)=A(k,j);A(k,j)=c;endforj=k:nsum=0;forr=k(k-l)sum=sum+A(k,r)*A(r,j);endu(k,j)=A(k,j)-sum;A(k,j)=u(k,j);endfori=l:nl(i,i)=l;endfori=(k+l):nsum=0;forr=k(k-l)sum=sum+A(i,r)*u(r,k);endl(i,k)=(A(i,k)-sum)u(k,k);A(i,k)=Ki,k);endend求A的列主元素三角分解：>>A=11111;12345;1361015;14102035;15153570;>>L,U=myfun（八）结果：L=1.000000001.00001.00000001.00000.50001.0000001.00000.75000.75001.000001.00000.25000.7500-1.00001.0000O4.000014.000034.000069.000000-2.0000-8.0000-20.5000000-0.5000-2.37500000-0.2500(2)求矩阵的逆矩阵A1:inv（八）结果为：ans=5-1010-51-1030-3519-410-3546-276-519-2717-41-46-41(3)检验结果：E=diag(lIlll)AEans=5-1010-51-519-2717-41-46-41程序：functiond=myfun(a,b,c,d,n)fori=2:nl(i)=a(i)b(i-l);a(i)=l(i);u(i)=b(i)-c(i-l)*a(i);b(i)=u(i);y(i)=d(i)-a(i)*d(i-l);d(i)=y(i);endx(n)=d(n)b(n);d(n)=x(n);fori=(n-l):-l:lx(i)=(d(i)-c(i)*d(i+l)b(i);d(i)=x(i);end求各段电流量程序：a(i)=-2;endb=25555555;c=-2-2-2-2-2-2-2;V=220;R=27;d=VROOOOOOO;n=8;I=myfun(a,b,c,d,n)运行程序得：I=8.14784.07372.03651.01750.50730.25060.11940.0477(1)求矩阵A和向量b的matlab程序:functionAb=myfun(n)fori=l:nX(i)=l÷0.1*i;endfori=l:nforj=l:nendendfori=l:nb(i)=sum(A(i,:);end求n=5时Al,bl及Al的2.条件数程序运行结果如下:n=5；Al,bl=myfun(n)Al=1.00001.10001.21001.33101.46411.00001.20001.44001.72802.07361.00001.30001.69002.19702.85611.00001.40001.96002.74403.84161.00001.50002.25003.37505.0625bl=6.10517.44169.043110.945613.1875cond2=cond(A1,2)求n=10时A2,b2及A2的2.条件数程序运行结果如下:n=10;A2,b2=myfun(n)A2=1.0000.ooo1.21001.33IO1.46411.61051.77161.94872.14362.35791.00001.2(XX)1.44(X)1.72802.07362.4B832.98603.58324.29985.15981.00001.30001.69002.19702.85613.71294.82686.27498.157310.60451.00001.40001.96002.74403.84165.37827.529510.541414.757920.66101.00001.50002.25003.37505.06257.593811.390617.085925.628938.44341.00001.60002.56004.09606.553610.485816.777226.843542.949768.71951.00001.70002.894.91308.352114.198624.137641.033969.7576118.58791.00001.80003.24005.832010.497618.895734.012261.2220110.1996198.35931.00001.90003.61006.859013.032124.761047.045989.3872169.8356322.68771.00002.00004.00008.0000I6.OO32.000064.00I28.OO256.00512.0000b2=1.0e+003*0.01590.02600.04260.06980.11330.18160.28660.44510.68011.0230cond2=cond(A2,2)cond2=8.6823e+011求n=20时A3,b3及A3的2-条件数程序运行结果如下：n=20;A3,b3=myfun(n)A3=0.00000.00000.00000.00000.000.0000O.(XX)O0.00000.000.000.000.00000.000.00000.00000.00000.000.00000.00000.000.00000.000.000.00000.000.000.00000.00000.00000.00000.00000.000.00000.00000.000.00000.00000.000.00000.00000.000.00000.000.00000.00000.00000.000.00000.00000.00000.0000O.(XX)O0.00000.0000O.O(XX)0.00O.(XX)O0.00000.00000.000.00000.000.000.00000.000.000.00000.00000.00000.00000.00000.000.00000.00000.000.00000.00000.000.00000.00000.00000.00000.00000.00000.000.0000O.O(XX)O.(XX)O0.00000.00000.000.00000.000.00000.00000.00000.000.00000.00000.000.00000.000.000.00000.000.00000.000.00000.00000.000.00000.000.00000.00000.000.00000.00000.000.00000.00000.00000.00000.00000.00000.000.0000O.O(XX)O.(XX)O0.00000.00000.00000.000.00000.00000.0000O.(XXX)0.0000O.(XX)O0.00O.O(XX)0.00000.000.000.00000.000.000.00000.00000.00000.00000.000.00000.000.00000.00000.00000.000.00000.00000.00000.00000.00000.00000.00000.000.0000O.O(XX)O.(XX)O0.00000.00000.0000O.(XX)O0.00000.00000.00O.(XXX)0.0000O.(XX)O0.000.00000.00000.000.000.00O.O(XX)0.000.000.000.00000.000.000.00000.000.000.00000.00000.000.00000.00000.0000Columns11through200.00000.00000.000.000.000.00000.00000.00000.000.00000.0000O.(XX)O0.00000.00000.00O.(XXX)0.00000.00000.000.00000.00000.000.000.00000
