FMINUNC cannot continue.

Hi, I am learning to use Matlab. I've copied below mentioned function from Matlab help and it is supposed to give me solution of (x) and value of function at (x). But when I run this (I provide input x=[2 2]) matlab gives me an error message.

"Failure in initial user-supplied objective function evaluation. FMINUNC cannot continue."

The function is shown below.

function [ f ] = myfun( x )
f = 3*x(1)^2 + 2*x(1)*x(2) + x(2)^2;    % Cost function
x0 = [1,1];
[x,fval] = fminunc(@myfun,x0)
end.

Please help.

Answer 1

[Grzegorz Knor]

You have to save your function myfun in separate file myfun.m

function [ f ] = myfun( x )
f = 3*x(1)^2 + 2*x(1)*x(2) + x(2)^2;    % Cost function
end

And then execute commands:

x0 = [1,1];
[x,fval] = fminunc(@myfun,x0)

Or simpler (in one line without additional file):

[x,fval] = fminunc(@(x)3*x(1)^2 + 2*x(1)*x(2) + x(2)^2,[1 1]);

See also:

http://www.mathworks.com/help/toolbox/optim/ug/brhkghv-3.html

[Rahat]

Thank you for your help.