FZERO error with matrix dimensions

I am trying to evaluate a function with fzero and getting the following error message - I am not sure why its throwing an error:

Error using fzero (line 246)

FZERO cannot continue because user-supplied function_handle ==> xsld failed with the error below.

Incorrect dimensions for raising a matrix to a power. Check that the matrix is square and the power is a scalar. To perform elementwise matrix

powers, use '.^'.

Error in moments (line 80)

[w,fv]= fzero(@xsld,w0,options);

The codes are below:

tol=10^-5; %tolerance 
w0=[0.1,200]; %wage interval
options=optimset('TolX',tol,'Display','iter');
options=optimset(options,'PlotFcns',{@optimplotx,@optimplotfval});
try    
[w,fv]= fzero(@xsld,w0,options);
    catch  
    cr = 50;
    return
end

And the function @xsld has the following codes, saved as a function file (I am only showing the codes that have the argument w):

function[xld] = xsld(w)
some codes...
RW = repmat(w.*(s.^gamma),1,ns); %wage income 
A = (1-((1-nu)*(1-alpha))).*(((1-nu)*(1-alpha))/w)^(((1-nu)*(1-alpha))/(1-((1-nu)*(1-alpha))));
lu = (((theta_r.^nu).*(1-nu).*(1-alpha).*(k.^(alpha*(1-nu))))/w).^(1/(nu + alpha*(1-nu)));
Ld = sum(mean(lu,2)) + ((B*psi)/w)^(1/(1-psi));
xld = (sum(mean((((theta_r.^nu).*((1-nu)*(1-alpha)).*(k.^(alpha*(1-nu))))/w).^(1/(nu + alpha*(1-nu))),2)) + ((B*psi)/w)^(1/(1-psi))) - Ls; 

Answer 1

[Matt J]

You can trap the occurrence of the error using

dbstop if caught error

[Girija Bahety]

Hi Matt,

Using dbstop helped to fix the issue but now I am getting another error.

Operands to the || and && operators must be convertible to logical scalar values.

Error in fzero (line 444)

while fb ~= 0 && a ~= b

Error in moments (line 79)

[w,fv] = fzero(@xsld,w0,fzerooptions);

What should I do here?

[Girija Bahety]

@Matt J I tried evaluating the xsld function using a scalar value for "w" and it gives me a scalar value for the function @xsld. So convinced the function is not vector valued.

[Matt J]

So convinced the function is not vector valued.

To make sure I would add a line to the end of xsld()

assert( isscalar(xld) , 'Unexpected vector-valued xld')

Now run the code with dbstop and see if the assert() is triggered.

[Girija Bahety]

Thank you Matt!