function X=gradientmethod(gradf,h,x0,maxit)
%a version of the gradient method which return maxit
%succesive aproximations for the minimum of f (given the gradient
%gradf of f)
X=zeros(length(x0),maxit);%reserving space
X(:,1)=x0;%setting the initial aprox. 
for i=2:maxit
    x=x0-h*feval(gradf,x0);%next approx.
    X(:,i)=x;%saving the current aprox.
    x0=x;%overwriting the previous aprox.
end