Invalid File Identifier?

The following code is giving this error:

Error using fprintf

Invalid file identifier. Use fopen to generate a valid file identifier.

fprintf(fileID, 'Newton Raphson Method \n')

%Open File for Writing
fileID = fopen ('Newton-Raphson Method', 'w'); 

syms x % Sets X as a symbolic variable
f = x.^3-x.^2+2.*x-2.4; % Function
f_prime = diff(f); %Derivative of function
error_tolerance = 0.001; %Tolarance
x_nod = 0.6; %Initial Guess for Root

%N = Iteration Number
%I = Guess Value
%Error = Error
fprintf(fileID, 'Newton Raphson Method \n')
 fprintf(fileID, '%-6s%-14.3s%-8.4s\n','n','I','Error') %Builds Table in CLC 
for n = 1:50 %Iteration Number
         f_nod = vpa(subs(f,x,x_nod));    %Calculates value at x_nod
         f_nod_der = vpa(subs(f_prime,x,x_nod));    %Calculate the Derivative at x_nod
     y = x_nod-f_nod/f_nod_der; %Newton-Raphson formula
    error = abs(y-x_nod); % Error formula
   fprintf(fileID, '%-6d%-14.3f%-8.4f%%\n',n,y,error)
   if error < error_tolerance % if Error does not meet tolerance established the function restarts
       break
   end
   x_nod = y; %If Error DOES meet tolerance then x_nod is set equal to y and sent down 
end

fprintf (fileID, '\nThe root is: %0.3f \n', y); %Displays Output
fprintf (fileID, 'The Error is: %0.4e \n', error);
fprintf (fileID, 'Number of Iterations: %d \n', n);

I've tried everything I can think of, what's wrong?

Answer 1

[Walter Roberson]

[fileID, msg] = fopen ('Newton-Raphson Method', 'w');
if fid<0
   error('cannot open file because: "%s"', msg)
 end