Issue with input arguements in a function

No matter how I change the function highlighted at the bottom I cannot get rid of the error: ??? Error using ==>@(f,t,n) Too many input arguments. I have read through Mathworks help description and examples of function arguments and I do not see a error in this function. Any help on this would be greatly appreciated.

syms t k n
evalin(symengine,'assume(k,Type::Integer)');

f = @(t)evalin(symengine,['subs(piecewise([0 <= t and t < 2,',...
    'sin((Pi*t^2)/4)],[t <= 2 and t < 3, 5*t-t^2-6], [t <=3 and t < 4, 0],',...
     '[Otherwise, t-4]),t=',regexprep(mat2str(x),' ',','),')']);

a = @(f,t,k) int(f*cos(k*pi*t/4)/4,t,-2,8);
b = @(f,t,k) int(f*sin(k*pi*t/4)/4,t,-2,8);

ERROR OCCURS HERE

fs = @(f,t,n) a(f,t,0)/4 + ...
    symsum(a(f,t,k)*cos(k*pi*t/4) + b(f,t,k)*sin(k*pi*t/4),k,1,n);

g = fs;

pretty(fs(g,t,25,1))

ezplot(fs(g,t,25,1),-2,8)
hold on
ezplot(f,-2,8)
hold off
title('Partial sum with n=25')

Answer 1

[Walter Roberson]

Urrr -- you are aware that just 2 and 3 lines down, you call fs with four arguments instead of 3 ??

[Carl]

Crap. Always the most obvious things that are overlooked.