# Where is the problem with my code. it never ends !!

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geometry geometry on 18 May 2018
Answered: Geoff Hayes on 18 May 2018
What is the problem with the following code?
It calculates the exponential coefficients fo fourier series of periodic function f(t).
when I run it the compilation never ends !! and I must close matlab and run it again.
function [an]=fc(f,T)
syms t n
n=-20:1:20;
an=(1/T)*int(f*exp(-1i*n*2*pi*t/T),t,0,T);
end
syms t n
f=rectangularPulse(t/4)*(abs(t)-1);
%f=rectangularPulse(t);
% f=sin(t);
Y=fc(f,20);
subplot(211)
stem(-20:1:20,abs(Y));
ylabel('|an|')
grid;
subplot(212)
stem(-20:1:20,angle(Y));
ylabel('<an')
grid;

Geoff Hayes on 18 May 2018
geometry - your function appears to be recursive
function [an]=fc(f,T)
syms t n
n=-20:1:20;
an=(1/T)*int(f*exp(-1i*n*2*pi*t/T),t,0,T);
end
syms t n
f=rectangularPulse(t/4)*(abs(t)-1);
%f=rectangularPulse(t);
% f=sin(t);
Y=fc(f,20); % <------------------
So it continually calls itself and without a stopping condition, it will call itself forever (!).