I have problem writing a matlab function

I want to write this function in matrix form.

The function is

I defined the vector as:

Then what is wrong with my code?

function [ ObjVall ] = objfun2( phen)
%UNTITLED Summary of this function goes here
%   Detailed explanation goes here

x=(5/pi)*phen(1:end,1)-6;
y=phen(1:end,2) - (5.1/(4*pi^2)).*(phen(1:end,1).^2 +x);
z=10*(1 - (1/(8*pi))*cos(phen(1:end,1)));
ObjVall=(y).^2 + z +10;

end

Answer 1

[the cyclist]

The coefficient

(5.1/(4*pi^2))

is multiplying the term you have called x, which is not correct.

It might have been easier to debug if you define

x1 = phen(:,1);
x2 = phen(:,2);

inside your function, which will make your MATLAB expression look more like the math equation.

Answer 2

[Sedi Ghan]

I don't know where is wrong in your code. However, I write your formula as follows and it works.

function [ ObjVall ] = objfun2( phen)
%UNTITLED Summary of this function goes here
%   Detailed explanation goes here
ObjVall= (phen(:,2) - (5.1/(4*pi^2))*phen(:,1).^2 + (5/pi)*phen(:,1)-6 ).^2+...
    +10*(1-(1/8*pi)*cos(phen(:,1))) + 10;
end

When phen is an N by 2 matrix, the output is an N by 1 array.

Answer 3

[Image Analyst]

Make sure x1 and x2 are column vectors (Nx1), NOT row vectors (1xN).