DFT in MATLAB

Just create a new file with extension .m and paste the code below in that .m file. Then Run it.

clear all;

clc;

x=input('Enter the sequence x(n) : ');

N=input('\nEnter the value of no. of points N : ');

L=length(x);

if(N>=L)

    x=[x zeros(1,N-L)];

elseif(N<L)

 error('Length of sequence must be less than no. of points.\n');

end

for k=0:1:N-1

    SUM(k+1)=0;

    for n=0:1:N-1

        SUM(k+1)=SUM(k+1)+x(n+1)*exp(-2*pi*j*k*n/N);     

    end    

end  

fprintf('DFT of x(n) is X(k)= ')

SUM 

%Graphics

figure(1);

subplot(2,1,1);

stem(abs(SUM));

subplot(2,1,2);

stem(angle(SUM));