逆broyden秩序法.txt

逆Bbroyden秩1法解非线性方程组实例

function[x,k]=broyden1(fun,dfun,x,tol,trace)
k=0;
f=feval(fun,x);
df=feval(dfun,x);
B=inv(df);
while(k<trace)
   k=k+1;
   s=-f*B';x=x+s;
   if norm(s)/(1+norm(x))<tol break;end
   f1=feval(fun,x);
   y=f1-f;f=f1;
   z=b*y';r=s*z;
   B=B+(s'-z)*s*B/r;
end