exp3

%dft of seq
clear all;
clc;
j=sqrt(-1);
xn=[1 2 4 6 2];
N=length(xn);
disp(N);
xk=zeros(1,N);
for k=0:1:N-1
    for n=0:1:N-1

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

    end
end

disp('THE DFT SEQUENCE IS:');
xk
disp('THE MAGNITUDE SEQUENCE IS:');
magxk=abs(xk)
disp('THE PHASE SEQUENCE IS:');
phaxk=angle(xk)

wk=0:1:N-1
subplot(5,1,1);
stem(wk,xn);
xlabel('k');                        %FOR LABELING X AND Y
ylabel('xn (db)');
title('Input Sequence-101915122');

subplot(5,1,2);
stem(wk,xk);
xlabel('k');                        %FOR LABELING X AND Y
ylabel('xk (db)');
title('DFT-101915122');

subplot(5,1,3);
stem(wk,magxk);
xlabel('k');                        %FOR LABELING X AND Y
ylabel('Magnitude(db)');
title('Magnitude Spectrum-101915122');

subplot(5,1,4);
stem(wk,phaxk);
xlabel('k');                        %FOR LABELING X AND Y
ylabel('Phase(degree)');
title('Phase Spectrum-101915122');

%IDFT
N=length(xk);
ixk=zeros(1,N);
for k=0:1:N-1
    for n=0:1:N-1

        ixk(k+1) = ixk(k+1) + ((1/N)*(xk(n+1)*exp(j*2*pi*k*n/N)));

    end
end
disp('THE IDFT SEQUENCE IS:');
ixk
subplot(5,1,5);
stem(wk,ixk);
xlabel('k');                        %FOR LABELING X AND Y
ylabel('ixk (db)');
title('IDFT-101915122');