How to use "fsolve" for optimizing the objective function?

How can I optimize the below function using "fsolve". It only takes input argument in the form of vectors but I have to pass input arguments to the below function in the form of matrix.

I am getting the below error while using the optimization toolbox

Error running optimization. Inner matrix dimensions must agree.

function f = object(w)
k=10;
B=20;

f = sum ((w(1,:)/(w(2,:).^w(3,:)*k)+((w(3,:)-1)*w(4,:)/B*w(3,:))));

end

Answer 1

[Alan Weiss]

You have many problems with your formulation. One of them is this line:

f = sum ((w(1,:)/(w(2,:).^w(3,:)*k)+((w(3,:)-1)*w(4,:)/B*w(3,:))));

You cannot divide a vector w(1,:) by a vector w(2,:) by using /. Instead, you must use ./, such as

f = sum ((w(1,:)./(w(2,:).^w(3,:)*k)+((w(3,:)-1).*w(4,:)./B.*w(3,:))));

While this change will allow your code to run, it does not end the problems with your code.

• It is bad form to name a function object, as this name is a MATLAB command.
• fsolve prefers a vector, not scalar, as the value of its objective function. Likely (but not definitely), you should get rid of the sum command in the definition of f.
• If I read your code correctly, then setting w(1,:) = 0 and w(3) = 1 will solve the equations. So why ask fsolve?

Alan Weiss

MATLAB mathematical toolbox documentation