# Complex Fourier Series in MATLAB

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Aijalon Marsh on 31 Oct 2020
Commented: Abhi Rane on 15 Jul 2021
Hello I'm tyring to solve this Complex fourier series porblem but for some reason when I solve for F1 I get an error and I'm not sure why because I have know warings so it should run smoothly. I would appreciate any assistance in resolving this issue and thank you in adavnce.
% Problem_1 the Complex Foruier series of the function f(x)
% f(x)=-1 -pi < x < 0
% f(x)=1 0 < x < pi
syms x n real
syms n integer
P = sym(2);
y = -1;
y1= 1;
Cn=int(y*exp(-1i*n*P*x/P),x,-P,0)+int(y1*exp(-1i*n*P*x/P),x,0,P);
Co=int(y,x,-P,0)+int(y1,x,0,P);
Ca=subs(Cn,cos(x),(exp(1i*x)+exp(-1i*x))/2);
Fn=(1/2*P)*Ca;
Fa=(1/2)*(1/P)*Co;
F1=symsum(Fn*exp(1i*n*P*x/P),n,-Inf,Inf);
display (F1)
VBBV on 1 Nov 2020
% f(x)=-1 -pi < x < 0
% f(x)=1 0 < x < pi
syms x n real
syms n integer
P = sym(2);
y = -1;
y1= 1;
Cn=int(y*exp(-1i*n*P*x/P),x,-P,0)+int(y1*exp(-1i*n*P*x/P),x,0,P);
Co=int(y,x,-P,0)+int(y1,x,0,P);
Ca=subs(Cn,cos(x),(exp(1i*x)+exp(-1i*x))/2);
Fn=(1/2*P)*Ca;
Fa=(1/2)*(1/P)*Co;
F1=symsum(Fn*exp(1i*n*P*x/P),n,-Inf,Inf);
display (F1)
Aijalon Marsh on 1 Nov 2020
Um I sorry but I'm not sure what you've done to improve upon my issue cause I still have the same problem.

VBBV on 1 Nov 2020
% if true
% code
%end
F1=symsum(Fn*exp(1i*n*P*x/P),x,[-Inf,Inf])
Use x as the summing variable.
Aijalon Marsh on 1 Nov 2020
ok thank you.
Abhi Rane on 15 Jul 2021
Does it work?