How should I pick input for jocabian() function im this case?

I want to calculate the gradient for a user-defined function using the jocabian() function.In the subfunction fcn, I pick subset from a larger parameter vector that is defined in the main program like

function fm = fcn(b)
``````
global T T_z T_e zt et
teta     =0;
zt       =b(1:T_z);           % Line-7 fcn%
et       =b(1+T_z:T_z+T_e);
dify     =zeros(T,T);
````

As one can see, [zt,et] are parameter I define in the subfunction fcn and on which I calculate the gradient. However, when I feed the input argument like the following and run the program,

[b,fun,flag]    = fminunc(@cov,b0);
v = [zt,et]';
dfb             = jacobian(fcn,v);

Matlab warned me that

    Error using fcn (line 7)
    Not enough input argument

I remark the location of error in the fcn function.I don't know why there is a problem. The definition of both et and zt seems without problem.Do I miss something?

Answer 1

[KSSV]

Check the line:

dfb  = jacobian(fcn,v);

In the above fcn is a function. You have to give input b to the function, which you have not.