How to plot the graph for a given signal over a range of frequency

How do I plot a discrete graph over the range of frequency given as [0 pi/8 pi/4 pi/2 pi] for the equation of signal x(n)=cos(w*n)

Answer 1

[KSSV]

w =  [0 pi/8 pi/4 pi/2 pi] ;
n = 1 ; 
x = cos(w*n) ;
plot(w,x)

Answer 2

[Sarvesh Kale]

Hi Saumya,

I am assuming you are trying to visualize different frequency discrete cosine waves, following is the code snippet that does this

w =  [0 pi/8 pi/4 pi/2 pi] ;
n=1:20;         % length of discrete signal 
figure ;        % makes a figure object 
subplot(5,1,1);
for i=1:5
x= cos(w(i)*n); % i will select a frequency from w 
subplot(5,1,i); % to plot on different plots inside same figure 
stem(n,x,'LineWidth',2); % stem function is used for discrete signals 
title([' w = ',num2str(w(i))]);
hold on ;     % draw on same plot 
end

the documentation of stem can be found in the following link https://in.mathworks.com/help/matlab/ref/stem.html

Hope this answers your queries