Fminsearch for matrices

Hi, how can i use fminsearch function for more than one dimension.

I am trying to do some thing like f=@(X)min(A-B*X), where A and B are given matrices. When I try to do fminsearch(f,x) i get the following error

??? Error using ==> minus Matrix dimensions must agree

so is there a way? Thanks

Answer 1

[Andrew Newell]

It sounds like the problem is with the dimensions of B*X. Does your initial value x0 have the same dimensions as A and B?

[srinadh]

so let me give u a sample code.

A=[1;1];

B=[2,1;4,3];

f=@(X)(A-B*X);

fminsearch(f,[1;2]);

[srinadh]

surprising thing is that when I define f=@(X)(A-B*[X(1);X(2)]); I still get an error. But for f=@(X)norm(A-B*[X(1);X(2)]);, it works perfectly!

[Andrew Newell]

Ah, I see the problem. FMINSEARCH can only accept functions that have a scalar as output. Fortunately, the function with the norm in it seems to be what you want.

[srinadh]

Oh, that's the issue. Thanks for the help :)