用三弯矩法求解三次样条插值函数(共3页).doc

精选优质文档-倾情为你奉上教材76页例题：用三弯矩法求三次样条插值函数s(x)。all clear;A=0 0 1 0.5 2 2.0 3 1.5;B=0 0.2 3 -1;m,n=size(A);for i=1:(m-1) h(i)=A(i+1,1)-A(i,1); f(i)=(A(i+1,2)-A(i,2)/h(i);endfor i=1:(m-2) u(i)=h(i)/(h(i)+h(i+1); l(i+1)=1-u(i); d(i+1)=6*(f(i+1)-f(i)/(h(i)+h(i+1);end u(m-1)=1; l(1)=1; d(1)=6*(f(1)-B(1,2)/h(1); d(m)=6*(B(2,2)-f(m-1)/h(m-1); C=2*eye(m); for i=1:(m-1) C(i,i+1)=l(i);