龙贝格积分-matlab通用程序.doc

数值分析课程的大作业,教材《数值分析》=input('请输入原函数f=','s');a=input('积分下限a=');b=input('积分上限b=');eps1=input('精度eps1=');T(1)=double((b-a)/2*(limit(sym(f),findsym(sym(f)),a)+limit(sym(f),findsym(sym(f)),b)));fork=2:4  sum1=0;  fori=1:2^(k-2)  sum1=sum1+subs(sym(f),findsym(sym(f)),(a+(2*i-1)*(b-a)/2^(k-1)));  end   T(k)=1/2*T(k-1)+(b-a)/(2^(k-1))*sum1;endfork=1:3  S(k)=T(k+1)+1/(4-1)*(T(k+1)-T(k));endfork=1:2  C(k)=S(k+1)+1/(4^2-1)*(S(k+1)-S(k));endR(1)=C(2)+1/(4^3-1)*(C(2)-C(1));k=3;while1  T(1)=T(2);  T(2)=T(3);  T(3)=T(4);  sum2=0;  fori=1:2^k  sum2=sum2+subs(sym(f),findsym(sym(f)),(a+(2*i-1)*(b-a)/2^(k+1)));  end   T(4)=1/2*T(4)+(b-a)/2^(k+1)*sum2;  S(1)=S(2);  S(2)=S(3);  S(3)=T(4)+1/(4-1)*(T(4)-T(3));  C(1)=C(2);  C(2)=S(3)+1/(4^2-1)*(S(3)-S(2));  R(2)=C(2)+1/(4^3-1)*(C(2)-C(1));  ifabs(R(2)-R(1))<eps1    break;  end  R(1)=R(2);endvpa(R(2),9)