how can I fix Warning: Imaginary parts of complex X and/or Y arguments ignored.

Hi

I'm trying to plot my code but this warning shows up

Warning: Imaginary parts of complex X and/or Y arguments ignored

clear all
close all
clc
T=2;
f=1/T;
w=2*pi*f;
t=-T/2:0.0001*T:T/2;
s=0;
for n=-100:100
    C=-8*1j*(-cos(n*pi/2)/(8*n*pi)+(sin(n*pi/2)/((2*n*pi)^2)));
    if n==0
        c=0;
    end
    s=s+C*exp(1j*n*w*t);
end
s=s;
plot(t,s)

[Walter Roberson]

    if n==0
        c=0;
    end

I suspect you should be assigning to C (upper case) instead of c (lower case)

Answer 1

[Adam Danz]

Your data contain complex numbers.

If this is unexpected, it indicates that there's a problem somewhere along your pipeline and you should figure out where the imaginary parts are coming from. For example, are you taking the square root of a negative number?

To find which elements of a vector are imaginary,

isImaginary = A ~= real(A);

If imaginary parts are expected and you'd like to remove them,

A_real = real(A); 

[Amir Shahmohamadi]

Hi

thanks for the support Adam ,It was very helpful.

[Adam Danz]

Glad I could help!