matlab hanging for the below code

Fs=10
t=0:1/Fs:1
x1=cos(2*pi*t*3)+cos(2*pi*t*4)+cos(2*pi*t*8)+cos(2*pi*t*10)
fft_x1=fft(x1)
fft_shift=fftshift(fft_x1)
mag=abs(fft_shift)
N=length(t)
f=-Fs/2:Fs/N:Fs/2-(Fs/N)
stem(f,mag)
fr=[]
for k=1:N
    sum=0
    for n=1:N
        out=x1(n)*exp((-i*pi*2*n*k)/N)
        sum=sum+out
        
    end
    fr=[fr sum]
    
end
fr=fftshift(fr)
mag1=abs(fr)
plot(t,x1)
title('signal time')
stem(f,mag1)

for this code matlab is hanging ,but for other programs matlab is working fine what is the problem in the code

Answer 1

[Image Analyst]

It doesn't hang for me.

But you should not use the name "sum" for your variable since it's the name of a very important built-in function that you will overwrite.

[Raj]

+1

Agreed!

[Shashidhar Kudari]

thanks for the answer, it solved my problem

[Shashidhar Kudari]

if we overwrite the inbuilt function ,then how should we correct that?

whether it gets corrected on restart of matlab?

[Walter Roberson]

You can clear followed by the name of the function.

Exception: if what you overwrote was clear itself, then

builtin('clear', 'clear')

If you ovewrote builtin and clear then you need the special behaviour

builtin clear clear

This will, as a special case, not invoke

builtin('clear', 'clear')

where builtin in the above line refers to whatever you overwrote builtin with.

Answer 2

[Raj]

Doesn't seem to be hanging for me!

Where are you having problem? Have you tried running in Debug mode?

[Walter Roberson]

It does not hang for me either.