MATLAB: How to use fminunc for more than one variable

Question

Hello guys,

I'm try to minime the cost of a function using fminunc

i have a function cost:

    function J = computeCostMulti(X, y, theta);
    J = 1/(2*size(y,1)) * sum(((X * theta)-y).^2);

So i try :

if true
  [optTheta,fVal]= fminunc(@computeCostMulti,tSet,profit,theta,options);
end

And got:

Warning: Struct field assignment overwrites a value with class "double". See MATLAB R14SP2 Release Notes, Assigning Nonstructure Variables As Structures Displays Warning, for details. > In fminunc at 200 Undefined function 'mtimes' for input arguments of type 'struct'. Error in computeCostMulti (line 16) T = 1/(2*size(y,1)) * sum(((X * theta)-y).^2); Error in fminunc (line 251) f = feval(funfcn{3},x,varargin{:}); Caused by: Failure in initial user-supplied objective function evaluation. FMINUNC cannot continue.

if i call computeCostMulti:
>>computeCostMulti(tSet,profit,theta)
ans =
623.5855

I really stucked here.

Whats the right way to do this?

Tks in advance

Answer 1

I solved my problem using anon functions

so i did:

f = @(x,y,z) function(tSet,preco,theta)

[optTheta, fVal, exit] = fmiunc(f,tSet,preco,theta,options);

And it's run!