求一份matlab程序设计 《其代码至少30行》

望各位高手能帮帮慢 急用啊

function [v,fval]=steepdecline(fun,x,x0,esp1,max)

if nargin<4

esp1=1e-3;max=1000;

end

if nargin<5

max=1000;

end

for i=1:max

p=jacobian(fun,x);

for j=1:length(x0)

p=subs(p,x(j),x0(j));j=j+1;

end

normp=0;

for j=1:length(x0)

normp=normp+p(j)^2;j=j+1;

end

if normp<esp1

break;

end

f=jacobian(fun,x);

f=jacobian(f,x);

for j=1:length(x0)

f=subs(f,x(j),x0(j));j=j+1;

end

lamda=(p*p')/(p*f*p');

x0=x0-lamda*p;

i=i+1;

end

v=x0;[m,n]=size(v);

for j=1:n

fun=subs(fun,x(j),x0(j));

j=j+1;

end

fval=fun;