MATLAB 最小二分法

MATLAB 最小二分法下面是我写的程序.但是一直ERROR.他好像提示是 fuction is not definedfunction f=fun(x)f=x-tan(x)e = input('精度要求 e = ');a = input('有根区间[a,b]取 a=');b = input('有根区间[a,b]取 b='); x1=(a+b)/2;s = b-a;while s >= e;x1=(a+b)/2;y=fun(x1);if y*fun(a)>0a=x1;b=b;s=b-a;elseif y*fun(a)