Error in fminsearch (line 200) fv(:,1) = funfcn(x,varargin{:});

I'm trying to get an optimised curve fir for my data, but i get the error

fun = @(x)(x(1).*(A).^2 + x(2).*(B).^2 + x(3).*(C).^2 + x(4).*(D).^2 -(E).^2);

x0 = zeros(1,4);

param = fminsearch(fun,x0);

[Ameer Hamza]

What are the values of A, B, C, D, and E.

[Tushar Verma]

Sorry , the post got submitted halfway through. A B C D E are vectors of 576x1 each and the full error is :

im trying to fit the data to a curve using : https://se.mathworks.com/help/matlab/math/example-curve-fitting-via-optimization.html

Unable to perform assignment because the size of the left side

is 1-by-1 and the size of the right side is 576-by-1.

Error in fminsearch (line 200)

fv(:,1) = funfcn(x,varargin{:});

Error in anaLiSis (line 263)

param = fminsearch(fun,x0);

Answer 1

[Ameer Hamza]

Objective function must return a scalar value, whereas, in your case, it returns a 576x1 vector. Following code uses norm() to take l2-norm of 576x1 to return a scalar.

A = rand(576,1); % example values
B = rand(576,1);
C = rand(576,1);
D = rand(576,1);
E = rand(576,1);

fun = @(x) norm((x(1).*(A).^2 + x(2).*(B).^2 + x(3).*(C).^2 + x(4).*(D).^2 -(E).^2)); 
x0 = zeros(1,4);
param = fminsearch(fun,x0);