FMINUNC : Failure in initial objective function evaluation.

Hi,

I'm using FMINUNC for a school project, I'm trying to find the original signal of a filtered signal with noise. Here's my code :

Main code

x1=x_triang_signal();
h=h_gauss_function(15,15,[0:1:30]);
y_nb=conv(x1,h,'same');
y=adgnoise(y_nb,30);
x0=zeros(length(x1),1);
fxo=criteria(x0,h,y,0.01)
xsol=optimize(x0,h,y,0.01);

This creates a triangle signal, a gaussian filter, gives the filtered signal then adds gaussian noise (i'm sure about all these functions). Then optimize :

Optimize (that uses FMINUNC)

function [xsol] = optimize(x0,h,y,alpha)

    options = optimoptions("fminunc");
    options = optimoptions(options,'Display','iter','MaxFunctionEvaluations',1000,'StepTolerance',1e-10,'SpecifyObjectiveGradient',true,'CheckGradients',true);

    % Run optimization solver
    xsol = fminunc(@(x)criteria(x,h,y,alpha),x0,options);
end

Criteria (the function i want to optimize, only considering x)

function [result] = criteria(x,h,y,alpha)
    result = norm(y-conv(h,x,'same'));
    for index=1:(length(x)-1)
        result = result + alpha * phi(x,index);
    end
end

Phi (a non-linear function that can change)

function [result] = phi(signal,index)
    result=abs(signal(index+1)-signal(index));
end

in the main code fx0 is 21.6754, however when running the main code i get :

Error using criteria
Too many output arguments.

Error in optimize>@(x)criteria(x,h,y,alpha) (line 9)
    xsol = fminunc(@(x)criteria(x,h,y,alpha),x0,options);

Error in fminunc (line 313)
        [f,GRAD] = feval(funfcn{3},x,varargin{:});

Error in optimize (line 9)
    xsol = fminunc(@(x)criteria(x,h,y,alpha),x0,options);

Error in mainTP3 (line 11)
xsol=optimize(x0,h,y,0.01);

Caused by:
    Failure in initial objective function evaluation. FMINUNC cannot continue.
    

Any help would be very appreciated !

[Ameer Hamza]

How is x_triang_signal defined?