MATLAB: Additional Inputs PDE Toolbox f coefficient

Question

My code below is generating some sort of error, however I'm not sure the error message is consistent with the problem which is actually occuring. The aim is to input additional parameters to the f-coefficient in the PDEToolbox:

function f = f_coeffunction_3v(location,~,N_w,mag)
N = 3; % Number of equations
nr = length(location.x); % Number of columns
f = zeros(N,nr); % Allocate f
Quad = zeros(1,nr); 
Quad(1:10) = 1;
Quad(12:end) = 2; 
jo = N_w.*mag ./ 2;    %Current Density Magnitude 
f(1,Quad == 1) = jo; f(2,Quad == 1) = 0 ; f(3,Quad == 1) = 0 ;
f(1,Quad == 2) = 0 ; f(2,Quad == 2) = jo; f(3,Quad == 2) = 0 ;
end 
N_w = 4; mag = 1;
f_fun = @(location,state)f_coeffunction_3v(location,state,N_w,mag); %Assign handle with correct functional form
f_vals = f_fun(location,[]); %Test values - identical to those from _2v.
specifyCoefficients(model,'m',0,'d',0,'c',c_coeff,'a',0,'f',@f_fun,'Cell',1);
Error using pde.CoefficientAssignment/checkCoefFcnHdlArgCounts (line 499)
Function specifying a coefficient must accept two
input arguments and return one output argument.

Answer 1

Change to:

specifyCoefficients(model,'m',0,'d',0,'c',c_coeff,'a',0,'f',f_fun,'Cell',1);

Remove the @ symbol in front of f_fun, because you already created f_fun as function_handle when you defined it.

Regards,

Ravi