Not enough input arguments

Hi, I cant understand why this wont run and what is meant by not enough input arguments. please help here is my code.

syms e q n
c=0;
g(n)=e/(2*(q+(1i*n*c)-((n)^2)));
 
N = 17;
l_start = ((N-1)/2)-2;
u_start = (N-1)/2;
l_end = l_start-N+3;
u_end = u_start-N+3;
f = diag(ones(1,N)) + diag(g(l_start:-1:l_end), -2) + diag(g(u_start:-1:u_end), 2);
 
F=det(f)==0;
 
F = det(F);
fimplicit(F)
xlabel 'epsilon'
ylabel 'omega'
xlim([0 5])
ylim([0 10])

the error codes i recieve are

% Not enough input arguments.
% 
% Error in sym (line 191)
%         n
% 
% Error in syms (line 227)
% defined = sym(zeros(1, length(args)));
% 
% Error in base2 (line 1)
% syms e q n

[Sriram Tadavarty]

Hi Seb,

Can you clear all the workspace and try? I see the output for your code placed and no errors.

Regards,

Sriram

Answer 1

[Steven Lord]

I suspect you've written or downloaded a sym.m that's taking precedence over the one included in Symbolic Math Toolbox. In my installation of release R2020a line 191 of sym.m is not just the letter n.

To check this, use the which function.

which -all sym

If that command shows other sym.m files that are not underneath matlabroot, rename them.